A tadpole Robin was the Muppet Babies version of Robin the Frog. He was largely confined to his bowl and could not communicate his thoughts to the other Muppet Babies, except for Baby Animal.
He first appeared in the first season episode "Close Encounters of the Frog Kind." Baby Kermit discovers he's an uncle because his "big sister" had babies. Robin wonders if he'll look like the "big frog" Kermit when he grows up.