Participatory Notes (?)

[Lucky Solomon]

I'm interested in loaning money to my GF for a quick flip she has under contract. Rather than have her sign a simple Note (and maybe a mortgage securing the Note), I would rather get a percentage of the profit from the sale of that flip. I've heard that such Notes are called "Participatory Notes."  Is this correct? If not, what are they called and where can I get a template I can use to draft one?