Happy Tree Friends/Dr. Seuss

FatKat as The Cat in the Hat (both are cats)

Cuddles as Conald

Giggles as Sally

Sniffles as The Talking Fish

Lumpy as Horton the Elephant

Pop and Cub as The Sour Kangaroo and The Young Kangaroo

Lifty, Shifty and other racoons as The Wickesam Brothers

Russell as Vlad Vandakoff

Truffles as The mayor of Whoville

Lammy as JoJo

Flippy as The Grinch (and Yertle the Turtle)

Flaky as Gertrude McFuzz

Petunia as Cindy Lou Who