Arthur Rizzic appeared in the Dinosaurs episode "The Mighty Megalosaurus." A mammal with a protruding snout, Rizzic escaped from the dinner table at the Sinclair Home, only to find Earl had destroyed his tree home. After Earl spared Rizzic following a heart-to-heart chat, the prey creature became B.P. Richfield's personal assistant.

Although this was Rizzic's only appearance, the puppet type would be recycled throughout the series, usually voiced by Brian Henson. Steve Whitmire actually performed the puppet in "Nature Calls," while Henson performed the voice.^[1]

Sources

1. ↑ Dinosaurs: The Complete Third and Fourth Seasons -- Audio commentary for "Nature Calls".