yeah...Deathclaws were chameleons...though...luckily after all of the other stuff West-Tek threw in there the things lost their camo ability...
Mirelurks were North American Horseshoe Crabs, with the king/queen apparently being Turtles, and a cut Catfish variant...all with heavy amounts of human/simian DNA...probably an experiment to make amphibious assault bio-weapons.
Mole Rats were...Mole Rats...just bigger. They're not native to North America, and a data file says they were made as sappers...to undermine defensive structures...It also says they have a programmed genetic kill-switch...which I think Moira accidentally found.
Wanimingos...I have no idea what their original creature was...those things are messed up.
Floaters are Flatworms...big angry flatworms
Centaurs are FEV gumbo...throw a bunch of stuff in a vat...pull it out...you got a monster. (really need to have random limbs for centaurs...arms, legs, animal legs, bug legs, tentacles, multiple heads)
(edit: oh man...I forgot about the S'Lanter ...sentient Raccoons...they were cut because they didn't mesh well with a world that had 1940s architecture, laser guns, aliens, Godzilla, Dr. Who, and an old Star Trek Prop that sends you back in time to make your ancestor leave the vault... ...ok...why were they cut again?)
that's about all of the factory made mutant animals I think...the geckos, regular rats, insects, and scorpions were "natural"
...hey...wait a minute...where's the spiders?