Simplify the following text for a Grade 6 native English-speaking person.
Original: The reticulate Gila monster lives in the southern region of the Gila monster 's range , while the banded Gila monster is a northern subspecies occurring primarily in the Mojave Desert .
Simplified: The Gila monster is a venomous desert lizard . The Gila monsterâ s name comes from the Gila River in Arizona , USA .