The Robotic Unicycles first appear is in the 1987 Teenage Mutant Ninja Turtles cartoon series, episode "Enter the Shredder". They are populary also known as "Roadkill Rodney", but that name comes not from the episode itself but from their subsequent appearances in the video game adaptions.
In their first appearance, they are used to capture a rhinoceros and warthog from a local zoo in New York (these would subsequently be used to create the mutants Bebop and Rocksteady). One captures Splinter when he finds and approaches the Technodrome. Two Robotic Unicycles fight the TMNT when they enter the Technodrome, failing miserably. At the end of the show, a Robotic Unicycle "rescues" Bebop and Rocksteady from the zoo cage the TMNT imprisoned the bumbling duo in. Telling them the Shredder wants to have a little talk with them.
Roughly cylindrical and balanced on a single wheel, Robotic Unicycles posses two powerful mechanical tentacles, a built-in blaster, a drill for tunneling and the ability to speak in monotone.