Adora's pet horse, who transforms into Swift Wind when Adora becomes She-Ra. Spirit is the day-to-day form; Swift Wind is the She-Ra mount form.
Spirit is the Etherian horse that Adora rides in her civilian Princess of Power identity. When Adora invokes her transformation with the Sword of Protection, Spirit transforms simultaneously into Swift Wind, the rainbow-winged unicorn mount.
Catalogue source: heman.fandom.com (CC BY-SA 3.0).