Claptrap's Secret Stash is a mission in Borderlands 2
You get it after taking Claptrap to Sanctuary
Objectives
Talk to Claptrap
Collect brown rocks
get Lost Staff of Mount Schulen
Defeat Destroyer of Worlds
Find Stash
Description
Claptrap: You helped me reach Sanctuary, minion, and for that you deserve a reward. I have a secret stash hidden very very far away from where I currently am. In order to find it, you have to perform a series of devious challenges. First, collect a few brown rocks for me. Then, defeat a bad-ass Skag. Then, go for the lost staff of Mount Schulen. Then, you should bring me the head of the Destroyer of Worlds. And then, you should dance for my enjoyment. Let me know when you are done with that job.