This is a small remix of Flexi Rex, adding a loop and the Clip on Holiday Hat.
2-3mm satin ribbon (available at craft/hobby shops) is best for the making loops to attach these to a tree. Wire ties (the type that bind new cables) is OK, cotton thread is fiddly to attach.
I've uploaded a Prusa Slicer project with 9 dinosaurs and hat parts. You can easily show/hide (right click → printable) to print as many or as few as you want, or to vary the hat colours by printing those separately.
The perimeters and infill of the parts have been customized to keep the model more-or-less balanced: when wearing the hat, hung from a string or standing on its feet.
Consider printing one or two extra hats, since the bottom part is delicate and easy to break. I used superglue to glue together the hat; it then snaps on to the eyebrows.
I've edited the hat to have a flat bottom for the bobble to attach. This makes it more reliable to print and easier to glue.
The author remixed this model.
Reduced size, added ring, tuned perimeter and infill settings for balance.