What three types of mammals are the common pigmy and water?

The question is a bit unclear. There aren't "common pigmy" and "water" as types of mammals. You might be looking for information about:

* Pygmy mammals: These are mammals that are significantly smaller than their larger relatives. Examples include the pygmy hippopotamus, pygmy marmoset, and pygmy elephant.

* Water mammals: These are mammals that live in or near water. Examples include whales, dolphins, seals, sea otters, and beavers.

Please provide more context or specify what you are interested in, and I can help you find the information you need.