Green’s Dictionary of Slang

Boob McNutt n.

[boob n.2 (1) + nut n.2 (1) / nutcase n.; ult. f. Boob McNutt, a strip cartoon character (running 1915–34) created by Rube Goldberg]

(US) a fool, a simpleton.

[US]C. Odets Awake and Sing! II i: Like Boob McNutt you know! Don’t go in the park, Pop – the squirrels’ll get you.
B. Hecht Spellbound [film script] You’d wind up in the arms of some Boob McNutt with spiked hair [HDAS].
[US](con. 1930s) R. Barber Night They Raided Minsky’s (1968) 282: Stage-door johnny, my eye. This is a regular Boob McNutt from the nut factory.