In a fantastic campaign where I was a player many moons ago, a unicorn named Morning Frost made a memorable appearance as an ally in a climactic battle early in the campaign...
And, as an homage to that great campaign, I DM'd a campaign that had an early climactic battle in a similar setting where the PCs also had a unicorn ally. Only this unicorn was named Dawnstrider...
You're welcome to use either one.