Sleepy Bat is a character introduced in Plants vs. Zombies: Garden Warfare 2. He is a bat who is in charge of the daily quests for the Lawn of Doom event. He is found near the fountain found far from the battlefield, resting underneath a tree near a special chest with a Halloween-themed appearance. Every time the player goes to Sleepy Bat daily, he will offer a challenge in which the player must find the key to the chest.
As mentioned above, Sleepy Bat will offer the challenge given to the player to find the key to the chest. When it begins, a bar above will show how further or closer you are to the key, similar to Hidey's Hide n' Find missions. Once you have found the key's location, you may either find it laying on the ground for you to pick it up, or a Champion must be fought for them to drop the key.
Once the key is retrieved, the player will be teleported back to Sleepy Bat and the chest. The player is able to open the chest and, once opened, the chest will either give the player a random Halloween-themed Customization item, or a Sticker Pack containing Halloween-themed consumables, as well as standalone consumables.
Since the Lawn of Doom event has ended, players will no longer be able to find Sleepy Bat at the fountain until potentially the next Halloween special event.