There are 21 Mondo Squads characters on this checklist, across 18 figures.
The most featured are
Morty (4 figures), Rick (4 figures) and Beavis (2 figures).
Beavis
Butt-Head
Daria
Enoch
Finn
Goofy
Greg
Harley Quinn
Ickis
Jake
Jane
Krumm
Max
Mondo Squads
Morty
Oblina
Poison Ivy
Pottsfield Pumpkin People
Powerline
Rick
Wirt