They say someone walked off with an African fat-tailed gecko over the weekend.
The Delaware Wildlife Rehabilitators Association in Bear noticed the little guy was missing earlier in the week.
A donation box was also wiped out.
Volunteers are worried because the lizard requires a special diet and a heat-controlled environment.
Online reptile dealers offer up to $2,000 for such an animal.
The center hopes whoever took it will bring it back.
