Mardi Gras VIP (3)
I believe the answer is:
rex
'mardi gras vip' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rex that I've seen before include "King's title" , "One in the palace" , "Oedipus - -" , "King (L.)" , "See 6" .)