Went off amphibian (4)
I believe the answer is:
newt
'amphibian' is the definition.
(I know that newt is a type of salamander)
'went off' is the wordplay.
'off' is an anagram indicator.
'went' anagrammed gives 'NEWT'.
(Other definitions for newt that I've seen before include "Went to find amphibian" , "Small, lizard-like amphibian" , "Small tailed amphibian" , "animal" , "found in pond!" .)