Fallout: New Vegas Creatures

Humanoid

 * Ghouls
 * Humans
 * Super mutants
 * Nightkin

Non-humanoid

 * Big Horner
 * Reptile Dogs
 * Dog
 * Molerat

Reptiles

 * Geckos
 * Little Gecko
 * Golden Gecko
 * Fire Gecko
 * Deathclaws
 * Mirelurk King

Arthropods

 * Radscorpions
 * Cazador
 * Mantis
 * http://fallout.wikia.com/wiki/Mirelurk
 * Radroach