Can't help you with growing creosote, but that's a handsome Trans Pecos!
Be sure to ask them what he prefers to eat- just in case they've been feeding them something other than what you plan to. They'll normally eat mice or rat pups, & usually take f/k or f/t just fine, but if you want to see them "smile" just offer a live fuzzy... (I get the same look with See's candy, lol.)