I hope you weren't talking about clay kitty litter. When he decides to eat that, it will be a huge vet expense and/or a dead iguana. I say when because he will. It would be very tempting for him.
I would even worry a bit about the pine-pellets. Pine is bad for most all pets, and pellets are bad when they are eaten, and iguanas are known for sampling everything.
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~Sara~
4 Leopard Geckos
4 ball pythons
1.0 Black-lined plated lizard (Lizzy Butt)
0.1 Burmese Python (Pixil)
5 Rats
6 Mice
1.1 Gerbils
1.1 Dogs (Ozzie and Mandy)
0.1 Cat (Isis)
0.0.1 Synodontis Catfish (Big Spotty Fish)
0.1 Convict Cichlid
0.0.1 blood parrot cichlid
0.0.1 African Featherfin Catfish