Moheek are non-hostile creatures native to SR388 showing features of fish or sea anemones. They crawl around the surface they are attached to, able to walk on walls or ceilings as well. Contrary to what its manual entry may seem to indicate, contact with any part of the creatures' bodies will cause damage to Samus. They are easily destroyed with Samus's beams.
"Moheek" could be a play on "Mohawk," referring to the creature's tendrils looking like a Mohawk.