Once Upon a Snowman is an upcoming animated short that takes place in the midst of the first Frozen movie. Though we essentially saw Olaf's origins in Frozen, the upcoming short will act as a bridge between his creation at the hands of Elsa and him bumping into Anna, Krisoff, and Sven.
We will be shown the snowman's first steps as he ventures through the mountains of Arendelle and discovers his love for Summer. Josh Gad reprises the role of Olaf and the short will also feature the voices of Kristen Bell as Anna, Idina Menzel as Elsa, Jonathan Groff as Kristoff, Frank Welker as Sven, and Chris Williams as Oaken the shopkeeper.
Once Upon a Snowman is directed by, Frozen 2 animation supervisor, Trent Correy and Dan Abraham, a storyboard artist who also worked on Frozen 2 — specifically the "When I Am Older" musical sequence. The animated short is set to premiere on Disney+ in just a couple of days on October 23rd.
So, with just days to go; Disney has shared an official trailer for Once Upon a Snowman. Check it out below (via Walt Disney Animation Studios):
Once Upon a Snowman comes to Disney+ on October 23rd, 2020.