Garyl

What happens when Taako casts Phantom Steed? Answer: GARYL. Per the spell, Garyl is a quasi-real horselike creature.

Initially, Garyl takes the form of a beautiful unicorn, with a big unicorn horn in rainbow colors. When he's first cast, Erasure plays in the background. His whinny travels up the octaves, perfectly tonally.

His mane is more like a mullet, but he is making it work. That's the amazing thing.

Eventually, Garyl miraculously sprouts another horn to become a majestic BINICORN.