Head to the Thorn ( north west side of new vegas. ) you get alot of creature hunting quests here from a lady called Red Lucy.
Head far north west up to the edge of the map, you'll find Jacobs town talk to a scientist in the main building.
Head far North east a radio signle pops up, follow it and you'll find a cave full.
go north north eaast of NV and the boomers will give you a hunt to perform.
What level are you, it's just most of these are for higher levels.
There are really few hunts that are quests, most of the creatures are just there to be shot or avoided just for fun.
thanks ime level 13 but can do level 27 quests
i miss some of the features fallout 3 had huge ghoul exterminating buildings and ant colonies exterminating but i really miss the underground subways they were kool.
just seems fallout 3 had better quests