Aquitian

Aquitians are humanoid aliens originating from the planet Aquitar that look very much like humans except for their heads. An Aquitian's head is slightly larger than a human's and, from the shape, possibly lacks the upper skull. The face of an Aquitian is covered with cartilaginous ridges that resemble a mask, encircling the entire head. Female Aquitian are capable of growing hair, which can be seen jutting out of the back of their ridges. They appear to feed on pure water for the sustainment of their life force. They also speak in literally bubbly voices, which can be annoying for the viewer because they cannot understand a word they're saying.

Notable Aquitians
Several Aquitians are named during Mighty Morphin Alien Rangers, and they are as follows:
 * The Aquitian Rangers
 * Delphine
 * Aurico
 * Cestro
 * Tideus
 * Corcus
 * Cestria

Aquitians in other Power Rangers series
Aquitians have become one of the most famous races of aliens in the Power Rangers universe, possibly for being one of the first shown and possibly for having their own series. Aquitians have appeared in several other series since Mighty Morphin Alien Rangers, including:
 * Power Rangers: Zeo, in which the Alien Rangers themselves appeared and Billy left to live on Aquitar and be with his lover Cestria.
 * Power Rangers: Time Force, in which an Aquitian is visible in the courtroom scene in the first episode in the year 3000.
 * Power Rangers: Wild Force, in which Red Alien Ranger Aurico appears in the episode Forever Red.
 * Power Rangers: SPD (an Aquitian can be seen in the training room).