___ the Lucky Rabbit, character in early Disney shorts (6)
I believe the answer is:
oswald
(Other definitions for oswald that I've seen before include "Lee Harvey . . . . . . assassinated President Kennedy" , "part of 1 25 [KING ;EAR]" , "Lee Harvey -, accused J. F. Kennedy assassin" , "JFK's assassin" , "King of the Northumbrians, d. 642 - President Kennedy's assassin, d. 1963" .)