Fallout: New Vegas Creatures

Humanoid

 * Ghouls
 * Humans
 * Nightkin
 * Super mutants

Non-humanoid

 * Bighorner
 * Centaur
 * Coyote
 * Dog

Reptiles

 * Deathclaws
 * Geckos
 * Fire gecko
 * Golden gecko
 * Little gecko
 * Mirelurk king

Unknown

 * Reptile dogs

Insects/Arachnids

 * Cazador
 * Giant ant
 * Mantis
 * Radscorpions