Snowball is the assistant drone of Mei. The drone is usually seen stored on Mei's ice tank of her back and is responsible for her ultimate, Blizzard. It can also be seen accompanying Mei in her emotes and highlight intros.
Snowball is woken up by Mei after nine years of inactivity. From then on, the drone is seen always by Mei's side, from giving her comfort after the discovery of her squad's deaths to handing her hot cocoa and ramen during her work. However, during a power outage, Snowball sacrifices its battery life in order to give Mei some remaining energy that aids her in building the Endothermic Blaster. By the end of the short, Snowball is woken up once again by Mei after being fully recharged from a solar-powered machine on her back.