Fallout: New Vegas Creatures

Humanoid

 * Ghouls
 * Humans
 * Super mutants
 * Nightkin

Non-humanoid

 * Big Horner

Reptiles

 * Geckos
 * Little Gecko
 * Golden Gecko
 * Fire Gecko
 * Deathclaws

Arthropods

 * Radscorpions