Those were the talking deathclaws. The original deathclaws were created pre-war by normaly genetic-engineering Jackson chameleons and mingling them with various other species. The Enclave afterwards managed to mutate them with FEV, and that was the first and only time FEV was involved with them.
You know, I do apologise. After going through my notes, I found out I was completely off. So I apologize. But I still stand by my statement that if the FEV can create things like the Super Mutants and what not, than it can do almost anything.
By the way, I always wondered: In FO1. the end scene I got had the Vault Dweller walking off into the Sunset with a messed up arm. FEV or Radiation? (On a side note, my cousin always got the same scene, but with no messed up arm. Wierd).