deathclaws are horrible things in NV. Deathclaws in F3 are just ridiculously easy.
In Fallout 1 no one really knew that they existed, they were like big foot. A lot of folks in the game said that they might have been a government project that had been long since, or some kind of demon that haunts the waste.
You also had the guard describe it:
"I'm Trent. I'm a guard for the Water Merchants. Our caravan was attacked... by a monster! So huge, so fast. It ate Joe, and took rifle shots and didn't flinch! So huge!"
that'll teach em' for jacking their prices so high