Stumblr
The act of using stumble-upon to find pictures to post on your tumblr account.
I was totally stumblring and found a picture of a cat with a hat!
Stumblr
someone who is a stalker on tumblr, one who stalks other tumblr accounts and claims that he/she happened to stumble across a tumblr account accidentally.
friend: why are you always checking out his account?
stumblr: no, i accidentally clicked on his account
friend: what, you clicked on his account for 20 days straight "accidentally" , you're a stumblr
stumblr: no, i accidentally clicked on his account
friend: what, you clicked on his account for 20 days straight "accidentally" , you're a stumblr