What have you been feeding him so far? Your cham can eat crickets, dubia roaches, superworms, silkworms, hornworms, and butterworms without issue. Out of all of these its not recommended to feed hornworms and superworms the most because they have a lot of fat and sometimes your cham refuses other food because they want you to give them superworms. Also veiled chams are known to accept fruits and vegetables from time to time. Mine have eaten romaine lettuce, kale, collared greens, apples, and carrots just to name a few. You're also gonna need calcium without d3 to dust your feeders.