Mizoujacks are docile animals that live in groups near geothermal vents. Their eggs are round and spiral-shaped, and the shells are incredibly strong. Lyza's notes mentioned freshly laid eggs are good.
When Riko, Reg, and Nanachi came across their nest the eggs were already beginning to hatch, but despite this they took and cooked them anyway. Even after being boiled and fried the hatchlings were still moving, though they were dead. They ended up being quite tasty.