In the website of ATMachine we can read an interesting series of articles about the old Lucas Arts adventures and between them, we can even find a wonderfull page with informations and screens for the beta version of Day of the Tentacle! In those images we can see different animations and unused items. Also, as we can read on Wikipedia, the game was originally intended to resemble Maniac Mansion more closely, with the player allowed to choose from among six characters who would have included a male poet named Chester, a female hippie named Moonglow described as “a New Age girl with sandals”, and Razor from the original game. This idea was dropped in preproduction to simplify the project. The art created for the character of Chester was eventually adapted for the characters of the sculptor twins in the final game.
Thanks to Celine for the contribution!