untitled public license.
So, how does this stuff work?
The Untitled Public License means that a work is still copyrighted, yes, but said work can be remixed and copied to one's liking, as long as they credit the original source.
For instance, if you were to remix, say, Steamboat Willie (let's just pretend that it was made last Tuesday and it was licensed under the UPL), you'd credit Walt Disney, as he made the work.
Can I profit off a work licensed under the UPL?
As long as it's yours, or the original creator allows you to if your work is a remix, yes you can.
Can I use this license against someone and make fun of their work?
Yes. If this weren't the case the U.P.L. would just be plain old ©opyright.