Here is a list of all the animals somewhat associated with the channel:
Emmett was Zach's old Rottweiler who was in a few videos.
Tiger is Zach's cat who is the main subject of the creepy cat series.
Maddy is Alexander's neighbor's Rottweiler who was 'blown up' with her owner in I Blew Up 6!: Man & Dog.
Rex is Zach's current dog. He is a Boxer-Pit-bull mix. Like Tiger, he also has a nickname which is Stupid Dog.
Donkey was Zach's stuffed animal pet who was a recurring 'character/topic in some videos. She was feisty, big, and funny.