Occamies and nature's shape-shifting creatures

'The Occamy is found in the Far East and India. A plumed, two-legged winged creature with a serpentine body, the Occamy may reach a length of fifteen feet. It feeds mainly on rats and birds, though has been known to carry off monkeys. The Occamy is aggressive to all who approach it, particularly in defence of its eggs, whose shells are made of the purest, softest silver.'
– Newt Scamander, Fantastic Beasts and Where to Find Them™

Photo courtesy of Warner Bros.

Occamy-catcher

Occamies can change size dramatically to fit the available space. Newt used a teapot to recover an escaped Occamy in New York City. By dropping a cockroach inside as bait, the enormous Occamy was tempted to shrink inside the teapot in pursuit of a tasty treat.

Photo courtesy of Warner Bros.

Shape-shifters

No animal can rapidly change size quite like the magical Occamy, but nature still has its fair share of shape-shifters.

Changing size or shape can be a handy survival tactic. Some animals shrink to save energy in harsh times or to squeeze into tight spaces. Others puff themselves up to look more threatening or less appealing to eat.

Photo courtesy of Warner Bros.

Shrinking lizards

Galápagos marine iguana (Amblyrhynchus cristatus)

When food is scarce, these lizards shrink their bodies by up to seven centimetres (three inches), losing around 20% of their regular length. This reduces the amount of food they need to survive.

Like the magical Occamy, marine iguanas can expand as well as shrink, returning to their original length when more food becomes available.

Climate change is likely to cause more frequent shortages of the marine iguana's main food, algae. The iguana's ability to shrink is therefore likely to play a big part in its future survival.

Amazing ability
Shrinking its body to save energy

Where to find them
Scrambling over the rocky coasts of the Galápagos Islands

Common shrew (Sorex araneus)

Shrews are already pretty small, but in winter these tiny mammals can shrink their skull, spine, brain, heart and lungs by around 15%.

Scientists think that by making themselves smaller, shrews need less food and so are more likely to survive the colder months.

Amazing ability
Shrinking its skull, spine and major organs

Where to find them
Scurrying through the undergrowth across much of Europe and Asia

Squeezing through a tight gap

Southern hagfish (Myxine australis)

The spineless, slime-producing hagfish would have no trouble squeezing into a teapot.

Hagfish can fit through gaps less than half the width of its body. Its loose skin allows blood to be forced towards its tail, making its front end slimmer. The blood then redistributes after it squeezes through.

A hagfish has no jaw, so it latches onto dead animals using its rough tooth plates. It then ties its body in knots, sliding the knot down to its heads and using it to lever off chunks of flesh.

Amazing ability
Compressing its body to fit through tight gaps

Where to find them
Muddy shallow waters off the coasts of Chile and Argentina

Desert rain frog (Breviceps macrops)

The tiny desert rain frog tries to look menacing by puffing itself up with air and wailing loudly.

Amazing ability
Expanding to scare off predators

Where to find them
Desert rain frogs can be found burrowing into the coastal dunes of Namibia

An egg-laying machine

Termite queens (Macrotermes bellicosus)

This termite queen started life the same size as other termites, around 13 millimetres (half an inch) long.

After mating, her body grew to around the size of a human finger, making it too big to leave the nest.

During a 20-year lifespan, termite queens can give birth to more than 200 million eggs.

Amazing ability
Filling its body with eggs, expanding to more than seven times its original size

Where to find them
Hidden within termite mounds in the savannahs of western and central sub-Saharan Africa

'Flying' without wings

Paradise flying snake (Chrysopelea paradisi)

Life in the jungle can be dangerous, so these snakes have evolved to 'fly' between trees to swiftly escape from predators.

They expand themselves by flattening their ribs to form a wide, curved underbelly that helps them glide through the air.

Amazing ability
Expanding their bodies to switch from slithering to 'flying'

Where to find them
Gliding through jungles in Southeast Asia