Green’s Dictionary of Slang

otis adj.

[the town drunk in the US TV comedy The Andy Griffith Show (orig. shown 1960–8)]

(US campus) drunk.

[US]Eble Campus Sl. Mar.
[US]Eble Sl. and Sociability 91: Reruns of The Andy Griffith Show, which originally aired from 1960 to 1968, have given otis ‘drunk’, a reference to the town drunk.