It's very much a regional drink in northern climates and has no connection to the the cartoon characters popular in the past century.
The Tom and Jerry
Watertown's Crystal Restaurant has become ground zero for Tom and Jerry's and many people consider a stop at the quaint downtown eaterie is a holiday must. Friday night the bar was crowded with Christmas enthusiasts seeking warmth in a decidely chilly night. The drink is so popular, other downtown spots are trying to replicate it, but while the mixture in the cup may be the same, the unique ambiance of the Crystal is hard to match.
Tom and Jerry (mixed drink) - Wikipedia, the free encyclopedia