Any of various large, thick-skinned, hoofed mammals such as the elephant, rhinoceros, or hippopotamus.
No, camels are not pachyderms. "Pachyderm" is an old term for a zoological ordering of animals that included elephants, rhinocerous and hippopotamus. It is now considered defunct. In modern usage...
Yes a rhino is a pachyderm because it is a large, thick skinned mammal.
No, the moose is not a pachyderm. That would include the elephants, rhinos and hippos.
No.
Thick Skin