missing tip of tongue? that sux!! as mentioned before, try tegu talk and/or the tegu
as for diet
for starters-- raw ground turkey, cooked egg,raw egg in a separate container, rats depending on size of tegu. also argentines like fruits but NO citrus fruits. try instead berries(blue, straw etc.)
maybe banana, but only once every 2wks. you can also try greens as well. also try mixing all this together and see if he/she likes it that way.
( add a little cod liver oil in raw ground turkey. its good for many reasons)
but to to above mentioned sites. good info
peace