Below is a list of all the available elements in the Monster group in Doodle God across all 4 episodes.

Episode 1:
Dragon
Ghost
Ghoul
Golem
Phoenix
Thunderbird
Treant
Vampire
Werewolf
Zombie

Episode 2:
Dragon
Ghost
Ghoul
Golem
Phoenix
Thunderbird
Treant
Vampire
Werewolf
Zombie

Episode 3:
The Monster group is not available in episode 3.

Episode 4:
Dragon
Ghost
Ghoul
Golem
Phoenix
Thunderbird
Treant
Vampire
Werewolf
Zombie