This is a modded and smaller version of the model released by Youtuber AvE.

https://github.com/Bumblefuck/copper-hammer/blob/master/2x2%20Version%20v7.stl

His was made for you to CNC from copper or aluminum and use as a real hammer. This is a toy. You will probably break your graphite up if you hit a bunch of stuff with this.

More recently he has made some pencil sized ones but not released the model for them.

https://www.youtube.com/watch?v=sPgYWHDktPU

If you print it in copper looking PLA you can get a similar effect to his.