Make complex pet comical, somehow (10)
I believe the answer is:
complicate
'make complex' is the definition.
(thesaurus)
'pet comical somehow' is the wordplay.
'somehow' indicates an anagram.
'pet'+'comical'='petcomical'
'petcomical' is an anagram of 'COMPLICATE'.
(Other definitions for complicate that I've seen before include "muddle" , "Make involved" , "Make less simple" , "Make intricate" .)