Admin skin

Hi to all

I would like to know how to change my admin skin ?

i saw on some private servers, admins were changing them own skin to monsters when they want !

and if i change myself to a monster, how to become back to my original character ?

/mymodel <path to -model-.ini>

something like /mymodel <path to -Babel-.ini> ?

HOPY:
for example:

/mymodel char\monster\hopy\hopy.inx