Which animal has three hearts?

Which animal has fingerprints so similar to human fingerprints that they can be difficult to distinguish visually?

Can an octopus taste with its arms?

Which animal can sleep while swimming by allowing one half of its brain to rest at a time?

Which marine animal has one of the fastest known strikes in the animal kingdom, using a specialized appendage to smash prey?

Which animal is famous for being able to regenerate lost limbs and, in some cases, repair parts of its heart, spinal cord, and brain?

Which animal is famous for a life cycle in which it can revert from an adult stage back to an earlier developmental stage under certain conditions?