The Yellow Unicorn Puffle is a Puffle Creature. It is available from the Puffle Wild app for iOS devices. It can be adopted after popping 50 of each yellow and white O'Berries on the bonus level after cleaning level 34 of Wild Woods.
According to the music video Awesome to be Rare, Yellow Unicorn Puffles have a variety of magical abilities, including their tears being able to heal wounds and freezing time, among others. Glitterpants the puffle is also seen to be able to talk, although it is unknown if all Yellow Unicorns have this trait.