This is the Pebblet Hammer from the video game Grounded.

This 3D printable file isn't endorsed by Obsidian Entertainment, Inc. and doesn't reflect the views or opinions of Obsidian Entertainment, Inc. or anyone officially involved with making the Pebblet Hammer. The Pebblet Hammer and Obsidian Entertainment and all related logos are trademarks or registered trademarks of Obsidian Entertainment, Inc.