Cauda

A horizontal, tail-shaped cloud (not a funnel) at low levels extending from the main precipitation region of a supercell Cumulonimbus  to the murus (wall cloud). It is typically attached to the wall cloud, and the bases of both are typically at the same height.

Cloud motion is away from the precipitation area and towards the murus, with rapid upward motion often observed near the junction of the tail and wall clouds. Commonly known as a 'tail cloud'.