Dangerous fish straying all over the place (8)
I believe the answer is:
stingray
'dangerous fish' is the definition.
(I've seen this before)
'straying all over the place' is the wordplay.
'all over the place' indicates anagramming the letters.
'straying' with letters rearranged gives 'STINGRAY'.
(Other definitions for stingray that I've seen before include "swimmer" , "menace in the water" , "Marine creature with venomous tail" , "Large fish with tail spine" , "Fish with venomous tail" .)