Animals in the class Amphibia spend part of their lives under water and part on land. Frogs, toads, and salamanders are amphibians. Many of these species must keep their skin moist by periodically returning to wet areas. All of them must return to water in order to reproduce because their eggs would dry out otherwise.
He then meets Mittens (Susie Essman), a female alley cat who bullies pigeons out of their food. Bolt (believing she's one of Calico's minions) forces Mittens to help him get back to Penny, and after Bolt ends up knocking Mittens unconscious into a letter box, the two start their epic journey westward on a truck.
Realizing that Penny truly does love Bolt, Mittens follows Bolt and explains. At the same time, the Bolt-lookalike panics during the show's filming and accidentally knocks over some flaming torches, setting the sound stage on fire with Penny trapped inside.