These builds are all based on their appearance in the 5th edition Monster Manual, but with one change. I do not have any appropriate Lego face tiles (Nixels do not have the right tone, but some of the new kryptomite faces might work), so I emphasized their goofiness by using ski pieces to give them clown feet.
This is a simple build focusing on the circular body and wings. With my emphasis on the feet, I made it a monopod to match the theme.
Another simple build, start with a 2x3 plate and add the limbs and eyes:
These are very similar to my Xorn build. Make three segments with clips, and roll them up:
Returning to a cube shape makes for another easy build:
This is another clip-and-roll build, but with the addition of a dome on top.
The dome is not connected to the rest of the build, but the axle just fits in the hole in the middle, and a gear on the bottom holds it in place: