Character played by Bryan Cranston (6)
I believe the answer is:
walter
(Other definitions for walter that I've seen before include "Sir - - Raleigh" , "Elizabethan navigator" , "Sir . . . . . . Scott, famous Scottish poet and novelist of 'Ivanhoe' etc" , "Bruno --;-- Mitty" , "- Mitty, Thurber's fantasist" .)