Id say a lace monitor. But not really sure.

As for volunteering at the sanctuary, that must be awsome. My house is probably the closest place with a number of exotics for 100+ miles. I would die to work at a place with a number of reptiles. Ive applied to veterinary offices and some other places, but with the economy low the vet's havent need anyone and the other places needed 2 years of college bio. But when i go off to college next year and start pre-vet, hopefully i will be able to get a job working with animals.