Hermit crab
To get into the shell, the hermit crab squeezes in backwards, using its four back legs to enter the shell. The back legs have hooks that anchor the hermit crab into the shell without difficulty. The next four legs are used for walking, while the front two are its chelipeds. The chelipeds are not equal in size: one is big and other is small. The larger one is used for grabbing prey and guarding the entrance to its shell. All together, hermit crabs have a total of ten legs, including the chelipeds and the rear legs used to anchor to the shell.