Slippery character from somewhere else (3)
I believe the answer is:
eel
'slippery character' is the definition.
(I've seen this before)
'from somewhere else' is the wordplay.
'from' indicates a hidden word.
'EEL' can be found hidden inside 'somewhere else'.
(Other definitions for eel that I've seen before include "Serpentine fish" , "Slippery swimmer (may be jellied)" , "Slimy fish" , "Slippery person" , "Almost scaleless fish" .)