Iggy is a part of the zoo attraction at the 3 Stooges Ghost Town.
Iggy is a male iguana. Its scaly body is entirely green.
Not much can be said about Iggy, expect that it seems at seems peace in its cage.
The New Scooby-Doo Movies
The Three Stooges rounded up the escaped animals (which did not include Iggy) and took them back to the amusement park, along with Mystery Inc. (who needed help getting the Mystery Machine out of a sand dune), where they were formally introduced to the animals, including Iggy, who was sleeping (or, at least, resting its eyes).
The park was reopened once the mystery was solved, and kids happily watched Iggy in its cage.
- It's unknown why Iggy hadn't escaped into the desert as well.