A Chain Chomp is an enemy with a outer steel core, tempered within the earth. There are many different sorts that appear in Paper Mario and outside. Many of the popular types consist of Dark Chomps, Red Chomps, Under Chomp and others.
Paper Mario: The Thousand-Year Door features traditional Chain Chomps, appearing in the Palace of Shadow. They are also found in the Pit of 100 Trials. Chain Chomps are usually found in underground areas. In Super Paper Mario, a Chain Chomp can be seen in the basement of Fort Francis.