Zombie Lila

Zombie Lila was the disguise of Lila.

Season one
She wanted the other members of her band to think she had been turned into a zombie so that they would sign over the rights of their new song to Roger (the band's manager) and herself.

Scooby-Doo! Frankencreepy
Some of the case (including the unmasking) was shown on Daphne Blake's webshow when AlexSuperFan2112 asked her if the gang was responsible for the break-up of the band.