"Hey! Good morning, Monstropolis. It's now five after the hour of 6:00 A.M. in the big monster city. Temperature's a balmy 65 degrees - which is good news for you reptiles - and it looks like it's going to be a perfect day to maybe, hey, just lie in bed, sleep in, or simply... work out that flab that's hanging over the bed!"
Monstropolis could possibly be named after the real life city of Minneapolis.
According to a DVD bonus feature, Monstropolis was founded after all of the monsters, who once co-existed with humans, were all chased off the mainland, and eventually moved to an island in an unknown part of the world (which Monstropolis is implied to be located) where they have lived ever since, and that the only way for them to enter human-inhabited areas was via closet doors.
In the original U.S. version, all crosswalk signals in Monstropolis read "Don't Stalk" and "Stalk" instead of "Don't Walk" and "Walk", respectively, but in the international releases, the crosswalk signals instead showed a four-clawed hand spread out for "Don't Stalk", and a two-headed monster walking for "Stalk".