The Scooty-Puff, Jr. is the vehicle Fry receives from Nibbler so he can infiltrate the Brain Spawns secret base, the Infosphere. It has a wind-up mechanism and it resembles a child's toy.
However, it falls apart when Fry tries to wind it to escape.
Fry is transported to the past to stop entering the future when Nibbler stops him. Fry shouts "Scooty-Puff, Jr. sucks!" when he is going back to the future. Nibbler bears this in mind.
The Scooty-Puff, Jr. is superceded by the Scooty-Puff, Sr., on Fry's second attempt to destroy the Brain Spawn Infosphere.