Shroomie

Shroomies is the unofficial nickname given to an unnamed spacefaring alien race. These creatures have a short, slender humanoid body and a mushroom-shaped head (the reason for their nickname) containing a pair of large, widely-separated oddly-built eyes and a complex structure on the neck region which might serve as a mouth.

This species appears to be very belligerent, territorial and yet reclusive. The Earth vessel Enterprise had an unfortunate encounter with them in 2151, in which the aliens failed to answer Captain Archer's hail and left, returning some hours later to attack the Enterprise, causing great damage. Two Shroomies boarded the Enterprise and killed a crewmember. A phase pistol shot by Archer had no effect on the aliens, though whether this is because they are naturally immune of have a shielding-like technology in their suits is unclear. A third encounter proved far better for the Enterprise, which had had its weapons upgraded and was able to cause serious damage to the Shroomies' ship, which departed instantly. The species was never encountered again after these incidents.

Appearances: Star Trek: Enterprise - "Silent Enemy"