Character: queen chrysalis
Chrysalis is the name of the changeling queen seen in Season 2, Episode 26: A Canterlot Wedding - part 2 (and seen, disguised as Princess Cadance, in the preceding episode). Although not named in the show, her name has been confirmed by sources within Studio B.
Physically, Chrysalis resembles a lanky alicorn, with her basic body shape being not unlike Princess Celesta's. However, her wings are insectoid in appearance, her horn is gnarled, her mane and tail resemble some sort of webbing, and her legs have holes through them. She also sports fangs.
Chrysalis appears to be the queen and undisputed ruler of the changelings, and is the only one to speak.