The term 'MONSTER' can be described as a big lizard, and the crossword solution for this is GILA. GILA monsters are large lizards native to the southwestern United States and northern Mexico. They are the only venomous lizards in North America and are known for their bright orange and black coloration. GILA monsters are slow-moving and can grow up to two feet in length. They are carnivorous and feed on small mammals, birds, and insects.