He can be catty (3)
I believe the answer is:
tom
'he' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for tom that I've seen before include "famous schoolboy" , "Cruise" , "Male feline" , "type pursuing queen" , "Boy - cat" .)