It's what he does
Over 5 and a half years ago a challenge was issued to get the Outskirts Scarab Gun from the tunnel.

It only took half a decade and a legend among men to pull it off, but grumpy finally snagged it. Do yourself a favor and check out this masterful effort.

O ma gah! He did it!
No way! Finally!
Shad0wFlame;773777 says:

Yeah, that.