Ira

Ira was an Umbrum and the daughter of Rabia.

History
In the guise of a fairy-like Umbrum, Ira befriended Radiant Hope at some point in the distant past, but after the unicorn brought Princess Cadance to the Shadow Prison, her true form was revealed to be a grotesque creature. She chased the two mares through the prison as the other Umbrum attempted to ambush them.

Behind the scenes
Ira first appeared in though her fairy-like form was never properly shown. In fact, her transformation was what was keyed the Umbrum's true nature of Radiant and Cadance, though the audience should already know their true motives, given Chrysalis's flashback regarding their sacking of the Crystal Empire.