“We have four-headed worms, six-legged frogs, and many other unusual creatures here as part of our work on bioelectricity and organ regeneration.”
Biologist Michael Levin said that. Charles Choi explains, in an article in LiveScience under the headline “Mutant tadpoles sprout eyeballs on their tails“.
BONUS: “What the Frog’s Eye Tells the Frog’s Brain”
BONUS: “Two legs, four legs, six legs, more!”