Despite the title being "Halloween is Grinch Night", Halloween is never once mentioned. This is possibly why the Random House Video release was renamed "It's Grinch Night!" and the Sing-Along Classics edition was retitled simply "Grinch Night".
This is the first animated Dr. Seuss media where the Whos are depicted to be fully clothed, which in the previous two, via Come il Grinch rubò il Natale (1966) and Horton Hears a Who! (1970), some of the Whos were depicted to be partially or fully undressed, even though they weren't given sensitive body parts as they are made for the youngest generations.
At one point, the Grinch gets into a "brickle-bush". The brickle-bush originally appeared in the Dr. Seuss story "What Was I Scared Of?" from "The Sneetches and Other Stories", even having the same phrase "I got brickles in my britches".