Curtis is Danvers Blickensderfer's pet rat in the Tales of a Sixth-Grade Muppet books.
Like Danvers' best friend Pasquale, Curtis often aids Danvers with his stunts. When scared, he likes to curl up in empty bags of Cheezy-Q's.
In the first book, Curtis jumps in front of Dr. Bunsen Honeydew's SHAMPUZ laser for Danvers. Though he seems normal at first, Curtis starts to grow larger and larger, eventually becoming kaiju-size. He terrorizes Mon Swoon's performance at the Fall on Ice Festival before returning back to his normal size, thanks to Bunsen and Beaker.
Curtis assumes the role of Side Dish — the sidekick to Danvers' superhero alter ego DareDanvers — in The Good, the Bad, and the Fuzzy.