Sludgepuppies

From Ben10versepedia

Sludgepuppies are a group of aliens that have had battles with the Plumbers on a normal basis. The first appearance of Sludgepuppies show up in the episode "My Big Fat Alien Wedding". They are giant, dark purple, mud-like alien species that can change into human forms. Their natural conditions are legless and a vague human blob. Females of that race have antennaes in their Sludgepuppy form. Sludgepuppies have the ability to stretch their limbs and create their own weapons from their composite mud. Being made a mud-like substances, makes them very weak if exposed to any amount of water in addition to fire. Examples of Sludgepuppies are CamilleMann, Mr. and Mrs. Mann, and Lucy.