From ErfWiki

Proposed Canon

A flying non-humanoid unit that is a fusion of pegasus, centaur and unicorn - a winged horse's body with a human torso in place where a horse's neck should be and a horned humanoid head.

Speculation

Unipegaturs can be used as a mount, at least when uncroaked.^{Erf-b1-p102Erf-b1-p103Erf-b1-p119Erf-b1-p120Erf-b1-p121}

Known Users

Royal Crown Coalition - but may be an independent faction in their own right like Marbits or Elves.