Large animal confused the panel (8)
I believe the answer is:
elephant
'large animal' is the definition.
(I've seen this before)
'confused the panel' is the wordplay.
'confused' indicates an anagram.
'the'+'panel'='thepanel'
'thepanel' with letters rearranged gives 'ELEPHANT'.
(Other definitions for elephant that I've seen before include "Largest land mammal" , "Large animal (in the room?)" , "Pachyderm hunted for ivory" , "See 18" , "I'll never forget" .)