Moonlight Sparkle

Moonlight Sparkle is Thaddeus' preferred riding mount and has been with him since roughly a year before he met the Antiheroes.
Though Moonlight Sparkle originally took the form of a warhorse and currently incarnates as a pegasus, her true nature is that of a celestial spirit that takes shape whenever Thaddeus petitions Esanihen for a mount. On occasions where Moonlight Sparkle takes a mortal wound in combat, the spirit sparkles out of incarnation, ready to be summoned back by Thaddeus' next prayer.
In any incarnation, she has navy blue coloration with silvery accents. In her pegasus form, this presents as a silvery mane, tail, and tufts around the hooves.
Thaddeus named her after a favorite character in Gloriana Heartwood's book, The Lover of the Gods. Despite having a telepathic link with Moonlight Sparkle, he has never asked how she feels about this.