Locking in some temporary changes from v.1.5 and introducing a new mechanic.

Voluntarily Changing Stats
Honey heist has a fun mechanic in which you can voluntarily move one point of Bear into Crime if you narrate a flashback where you and the other bears planned the heist in a seedy bar as well as being able to move a point from Crime into Bear if you eat a load of honey. To approximate this for Mimics, players can move a point of Mimic into Chair by narrating a time when their current disguise tricked some adventurers into being a tasty meal and relating it back to hunting the Wizard and can also move a point from Chair into Mimic by destroying one of the Wizards Animated Objects in the tower. The intention with the second is that players don't need to roll to take out the object but it will leave evidence behind that they may need to deal with.

Suspicion
A new tool for Game Masters running Eat The Wizard is the Suspicion Level within the Wizard's Tower. This is meant to help track how susceptible the Wizard himself or the Furniture guarding his abode are to the Mimic's disguises. If the GM isn't sure if the players should just get away with something or if they want to give the players an extra chance to succeed but with some risk, they can make a Suspicion Roll. It doesn't affect a player's stats like normal rolls do, but cumulating failures mean the denizens of the tower are increasingly likely to suspect something is amiss when investigating.

Incapacitating the Wizard
While this has not been introduced as a hard rule, the text "Infiltrate the Tower, Incapacitate the Wizard, Consume!" was added to give a brief statement of direction for the players but also to insinuate that you have to "Incapacitate the Wizard" before you can eat him. This accomplishes a few things but mainly it mitigates the possibility that a player finds the Wizard and immediately attempts to eat him ending the game on a success. The implication that the Wizard must be incapacitated first subtly encourages players to plan and scheme more elaborate ends to the game once they've found the Wizard in the Tower.

A Clarification
Only because it came up in a recent play-through: Regardless of the lore or abilities of Mimics in other games, it's intended here that the Mimics have only one disguise form, though they may have the opportunity to change it throughout the game. When successfully changing a disguised form after being Zapped it was originally intended that they could pick for themselves this time around which disguise they are though of course, you could have them roll as well. Similarly, while the initial disguised forms of the Mimics are random you could let your players choose if you'd like.