This is an experimental, one-character variable color font. It contains only one character, the poo emoji 💩. It has one axis, "crap", which goes from 100 to 900.
You can see Mr. Poo in action here! If he's all black and/or doesn't animate, your browser doesn't fully support variable color fonts yet.
Your browser needs to support variable fonts and color fonts of the COLR/CPAL format. Currently this is only Safari 11 and Chrome 62 on OS X High Sierra.
It's a bit messy, but: build the ufo files in the source directory, then inject COLR/CPAL tables by running scripts/pathcolorcpal.sh (source found in scripts/colr-cpal-tables.ttx).
Then, uhm, dump the font with ttx/FontTools and hack away until it's working. These are lousy instructions, I know, but the truth is I've been hacking at this on-and-off for the past months and I forgot the exact path to the current VariablePooDemo.ttf file. But I'm more than willing to work out problems or answer your questions (even dumb ones (especially dumb ones)), so ping me at my site or over at Twitter.