Baby Robin was the Muppet Babies version of Robin the Frog. He was a tadpole who 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.
Robin appeared again in the episode fourth season episode "Adventures in Muppet-Sitting."
Baby Robin, like Baby Animal, only speaks in baby babbles, but for one brief scene in "Close Encounters of the Frog Kind," his mouth movements sync up to one of his thoughts.