Fold 1 First Reader
Go, Octopus, Go!An octopus has three hearts.
The octopus set
Six books about one animal. Each fold goes deeper than the one before, and every fact in all six comes from the same fact bank.
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An octopus has three hearts. Drag the slider to read all six versions, word for word from the books, then try another fact.
Fold 2 Read Together
Hello, Octopus!An octopus has three hearts. Thump, thump, thump!
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsAn octopus has three hearts.
Fold 4 Explorer
Octopus: Escape Artist of the SeaAn octopus has three hearts. Two small hearts push blood through the two gills, where it picks up oxygen. The third heart pumps that blood around the rest of the body. Octopus blood is blue when it is carrying oxygen.
Fold 5 Field Guide
Octopus: A Field GuideAn octopus has three hearts. Two of them, the branchial hearts, sit one at the base of each gill and push blood through the gills to pick up oxygen. The third, the systemic heart, pumps that fresh blood around the rest of the body. The blood is blue when it is carrying oxygen, because an octopus carries oxygen on hemocyanin, a protein built around copper.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindAn octopus has three hearts. Two branchial hearts, one at the base of each gill, push blood through the gills, where it picks up oxygen. The third, the systemic heart, then pumps that oxygen-rich blood around the rest of the body. Octopus blood is blue when it is carrying oxygen, because it carries oxygen on hemocyanin, a copper-based protein, where our blood uses iron-based hemoglobin.19
Fold 1 First Reader
Go, Octopus, Go!An octopus can taste what it pats.
Fold 2 Read Together
Hello, Octopus!An octopus can taste with its suckers. Squish! What does this shell taste like?
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsAn octopus can taste with its suckers.
Fold 4 Explorer
Octopus: Escape Artist of the SeaAn octopus's suckers can taste what they touch, as well as feel it. So an octopus can reach into a dark crack and tell what it is holding without seeing it.
Fold 5 Field Guide
Octopus: A Field GuideAn octopus can taste with its suckers. Sensory cells in the suckers detect chemicals as well as touch, so an arm can tell what it is holding without the octopus seeing it.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindAlong each arm run the suckers, and an octopus's suckers can taste what they touch. Sensory cells in the suckers detect chemicals as well as touch, so an arm probing a crevice can tell what it is holding without the octopus seeing it. In 2020 researchers working with the California two-spot octopus identified a family of chemotactile receptors, sensors that taste by touch and are found only in cephalopods. They respond to poorly soluble chemicals, ones that do not dissolve easily in water, on the surfaces of prey and other animals.15
Fold 1 First Reader
Go, Octopus, Go!An octopus can fit in a gap.
Fold 2 Read Together
Hello, Octopus!An octopus has no bones. Squeeze, squeeze! It can slip through any gap bigger than its beak. Can you make yourself small?
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsAn octopus has no bones, so it can squeeze. It can fit into any gap bigger than its beak.
Fold 4 Explorer
Octopus: Escape Artist of the SeaAn octopus has no bones, so it can squeeze through any gap bigger than its beak. Its soft body stretches and flattens to follow the beak through. A fully grown giant Pacific octopus can fit through a hole about the size of a lemon.
Fold 5 Field Guide
Octopus: A Field GuideAn octopus has no bones and no shell, so its soft body can flatten and stretch to follow its hard beak. Aquarium keepers go by a simple rule: if the beak fits, the octopus fits. An octopus can squeeze through any gap bigger than its beak. A fully grown giant Pacific octopus can get through a hole about the size of a lemon.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindAn octopus has no bones and no shell, so it can squeeze through any gap bigger than its beak. The beak is the only large hard part of the body, a parrot-like bite at the center of the ring of arms, and everything else can flatten and stretch to follow it through. Aquarium keepers work on a simple rule: if the beak fits, the octopus fits. A fully grown giant Pacific octopus can pass through a hole about the size of a lemon.4
Fold 1 First Reader
Go, Octopus, Go!Lots of octopuses can get red.
Fold 2 Read Together
Hello, Octopus!Most octopuses can change color. Orange, orange… ta-da! Speckly brown, like the rocks. What color would you be?
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsMost octopuses can change color. They can make bumps on their skin, as well.
Fold 4 Explorer
Octopus: Escape Artist of the SeaAn octopus can change the color and pattern of its skin in a flash. It can raise bumps and spikes, too, so it looks like rock, coral or seaweed. Most octopuses use these tricks to hide, and to send signals to other animals.
Fold 5 Field Guide
Octopus: A Field GuideMost octopuses can change the color and pattern of their skin, either to blend in and hide or to send signals to other animals. They can change its texture too, raising bumps, ridges and spikes that look like the rock, coral or seaweed around them. With color and texture working together, an octopus can look like part of the seabed instead of an animal sitting on it.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindAn octopus can change the color and pattern of its skin, and it can change the texture too, raising bumps, ridges and spikes to look like the rock, coral or seaweed around it. Most octopuses use the skill in two ways. Going pale, dark, blotchy or striped to match the surroundings hides an octopus from predators and from the animals it hunts, while the same changes can show mood or intent, warn off a rival or startle an attacker.32
Fold 1 First Reader
Go, Octopus, Go!Lots of octopuses can jet off!
Fold 2 Read Together
Hello, Octopus!Puff! Most octopuses can squirt a cloud of dark ink. Whoosh! Away they zoom. Can you say whoosh?
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsMost octopuses can squirt ink. The ink hides the octopus as it slips off.
Fold 4 Explorer
Octopus: Escape Artist of the SeaMost octopuses can squirt a cloud of dark ink when danger comes. The ink hides the octopus while it gets away. It can also zoom off by jet, squirting water out of a tube called the siphon.
Fold 5 Field Guide
Octopus: A Field GuideMost octopuses can squirt a cloud of dark ink when an attacker comes close. The ink is mostly a dark pigment called melanin, mixed with mucus, and it leaves the body through the siphon. At the same moment, the octopus often turns pale and shoots away by jet propulsion, forcing water out through the siphon. The attacker is left facing a dark cloud while a hard-to-see octopus escapes.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindMost octopuses can squirt a cloud of dark ink that hides them from an attacker while they get away. The ink is made in an ink sac inside the body and is mostly dark melanin pigment mixed with mucus. It leaves through the siphon, usually as the octopus jets off, and an octopus often pales, inks and jets all at once, so the attacker is left facing a dark cloud while a hard-to-see octopus shoots away.44
Fold 1 First Reader
Go, Octopus, Go!Some octopuses can sit in a coconut.
Fold 2 Read Together
Hello, Octopus!Some octopuses carry a coconut house. Tip, tap, tip, tap. The veined octopus hides inside! Where would you hide?
Fold 3 Early Reader
Octopus: Eight Arms, Three HeartsSome octopuses lug coconut shells across the sand. Then they hide inside!
Fold 4 Explorer
Octopus: Escape Artist of the SeaSome veined octopuses carry a shelter with them! The veined octopus of Indonesia digs up halves of coconut shells and carries them across the seabed. Later it fits the two halves together and hides inside.
Fold 5 Field Guide
Octopus: A Field GuideSome veined octopuses carry their shelter with them. The veined octopus of Indonesia digs up halves of coconut shell, carries them across the seabed and later fits them together as a shelter to hide inside. Carrying the shells slows the octopus down, because it has to walk on stiff arms with the shells held underneath. The payoff only comes later, when it stops somewhere open and needs a place to hide.
Fold 6 Deep Dive
Octopus, Unfolded: The Science of a Soft-Bodied MindSome veined octopuses carry a shelter with them. The veined octopus of Indonesia digs up coconut-shell halves, carries them across the seabed and later fits them together as a shelter to hide inside. Carrying the shells slows the octopus down, because it has to walk on stiff arms with the shells held underneath, so it gains nothing until it stops somewhere open and needs a hiding place. That delayed payoff is why the biologists who described it in 2009 called it tool use. Coconut carrying is known only from the veined octopus.58
The facts behind it: An octopus has three hearts. Octopus blood carries oxygen on hemocyanin, a copper-based protein that makes the blood blue when it is carrying oxygen. 5 published sources
The fact behind it: An octopus's suckers can taste what they touch. 3 published sources
The facts behind it: An octopus can squeeze through any gap larger than its beak. An octopus has no bones and no shell. An octopus can squeeze through small gaps. 6 published sources
The facts behind it: Octopuses can change the color and pattern of their skin, both to blend in and hide and to send signals to other animals. Octopuses can change the texture of their skin as well as its color, raising bumps, ridges and spikes to look like the rock, coral or seaweed around them. 5 published sources
The facts behind it: Most octopuses can squirt a cloud of dark ink that hides them from an attacker while they get away. An octopus can make a fast getaway by jet propulsion: it fills its body with water and forces it out through a tube called the siphon, which shoots it away. 5 published sources
The fact behind it: The veined octopus of Indonesia digs up coconut-shell halves, carries them across the seabed, and later fits them together as a shelter to hide inside. 3 published sources
Fold 1 · First Reader · Tide pool
Go, Octopus, Go!
- Ages
- 4–6
- Trim
- 6 × 9 in
- Pages
- 24
- Words
- 109
An octopus has three hearts. It can taste what it touches and fit in a gap; most octopuses can turn red and jet off, and some sit inside coconut shells. Go, Octopus, Go! is a first book for a child to read alone: almost every word is short and spelled the way it sounds or is a common word learned by heart, and four words (octopus, hearts, taste, coconut) are taught with pictures up front. One or two short sentences sit in a cream panel over each full-page picture. Every fact in it was checked against published sources.
Fold 2 · Read Together · Sunlit shallows
Hello, Octopus!
- Ages
- 6–8
- Trim
- 8.5 × 8.5 in
- Pages
- 32
- Words
- 257
Splish, splash! Who lives down in the sea? Meet an octopus with eight arms to count, three hearts that go thump, thump, thump, and suckers that can taste. Watch it squeeze between two rocks, then puff! Out comes a cloud of ink. Read with Mila and Omar: every spread has a sound word to join in on and a question to answer while an adult reads aloud. Notes at the back explain the fact behind each picture and name their sources.
Fold 3 · Early Reader · Coral reef
OctopusEight Arms, Three Hearts
- Ages
- 8–10
- Trim
- 6 × 9 in
- Pages
- 32
- Words
- 548
An octopus has three hearts and no bones. It tastes with its suckers, and it can squeeze into any gap bigger than its beak. Most octopuses can change color, or squirt ink and slip away. Some even hide inside coconut shells. Octopus: Eight Arms, Three Hearts is written for children who have finished their first readers and now read on their own, with short sentences, a picture on every reading page, eight pictured Words to know at the front and a quiz at the back. Every fact in it was checked against published sources.
Fold 4 · Explorer · Kelp forest
OctopusEscape Artist of the Sea
- Ages
- 10–12
- Trim
- 8 × 10 in
- Pages
- 40
- Words
- 2,182
How does an animal with no bones slip out of its tank at night? Why does it need three hearts? In five short chapters, young explorers meet the octopus up close: suckers that taste, blood that turns blue when it carries oxygen, skin that changes color in a blink, and a jet that shoots it out of trouble. They watch a mother guard her eggs and meet the giant Pacific octopus. Wow! boxes, diagrams, a quiz and a glossary help along the way, and Mila and Omar, who present the octopus video episode, ask questions as guides. Every fact is checked against published sources.
Fold 5 · Field Guide · Open ocean
OctopusA Field Guide
- Ages
- 12+
- Trim
- 8 × 10 in
- Pages
- 48
- Words
- 5,492
An octopus has three hearts, blood that turns blue when it carries oxygen, and suckers that can taste. It has no bones, so it can squeeze through any gap bigger than its beak. This field guide takes you inside the animal: the skin that can change color in a fraction of a second, the veined octopuses of Indonesia, some of which carry coconut shells to hide in, and the mother who guards her eggs until they hatch. Inside are labeled diagrams, species cards, things to try and field notes from Mila and Omar. Every fact is checked against published sources, listed at the back.
Fold 6 · Deep Dive · The deep
Octopus, UnfoldedThe Science of a Soft-Bodied Mind
- Ages
- 12+
- Trim
- 6 × 9 in
- Pages
- 64
- Words
- 7,734
An octopus has three hearts and blood that runs blue when it carries oxygen. It can squeeze through any gap bigger than its beak, and a common octopus keeps roughly two-thirds of its neurons outside its brain, mostly in its arms. Octopus, Unfolded is the deep end of The Paper Wild: drawn from the same bank of checked facts as the picture book, told in full for readers of twelve and up, with diagrams, endnotes and every source listed. Where scientists are still finding out, it says so.
Pilot edition, 2026. Printed on demand as premium-color paperbacks. See every fact they use