D.J. and C.J. only show up at the end, and are the only kids who didn't transform into animals.
Sparky's human form makes a return in this episode.
T.U.F.F. Puppy - At one point, after becoming a cat, Jessie indirectly mentions Kitty Katswell (as "that beautiful cat agent from that show about animal agents") from T.U.F.F. Puppy, another show created by Butch Hartman, with Jessie wanting to become an agent like her. Both Jessie and Kitty are voiced by Grey Griffin.