This appears to be an update to the Greenbrier (Dollar Tree) Starsong pegasus.
In 2024, unicorns based on this design began appearing. These ones are 5″ tall branded Fashion & Fun by Just Pretending (Greenbrier International label).
Toy Box Pony Set:
This set includes one 4.25″ earth pony, one 3″ earth pony, and one ~3″ unicorn (the unicorn is slightly shorter than the earth pony).