I have read that in mantras of 'Krodh-Bhairav' like 'Krum, 'Krom', etc.!
I think it represents 'Krodh-Bhaav' (Angry Form) of Krodh-Bhairav.
Other names of the same i.e. Krodh-Bhairav are: PrithiviPati, BhootDaamar, VajraPaani, MahaaKaal, etc!
A request: I want to know about this specific mudra (pose of hands) in the following picture:-
http://i15.tinypic.com/4mmb2u8.jpg