Special clouds

Mammatus clouds.

Mammatus clouds are actually altocumulus, cirrus, cumulonimbus, or other types of clouds that have these pouch-like shapes hanging out of the bottom.

Orographic clouds.

Orographic cloudsget their shape from mountains or hills that force the air to move over or around them.

Lenticular clouds.

Lenticular clouds are shaped like lenses or almonds or...flying saucers! They may get their shape from hilly terrain (another type of orographic cloud) or just the way the air is rising over flat terrain.