I can see where @CheeseChameleon2007 is coming from, I thought it was an extremely young rhinoceros iguana at first, but I can definitely see now that it's a tegu
I think it is the quality of the photo which had led to some confusion.
Tegus have those prominent bulging cheeks which could be mistaken for the equally bulging jowls / subtympanic shield of the rhinoceros iguana along with the dullish colouration (would be quite darker with a rhino iguana though) and thick set body that the rhino iguana has.
I think thats why @CheeseChameleon2007 got a bit confused about its ID, which is understandable in some ways.
But yes, this is a tegu and definitely not a rhinoceros iguana which as @Great Argus points out would have a prominent crest running down the spine.