Sort of what it sounds like: a Christmas Tree, but also a T-Rex. And naturally it's eating elves.
Source files: T. Rex Easy Print and Glue
Proportionally, a 24" pre-lit tree works well. Look for something with a solid base, wire branches and trunk, and minimal additional "stuff".
The attached files include sources (remix from this) for 3D printing; the hips can be printed or lasered (both files included). The remix work included trimming, scaling, and inserting features to connect to the tree & hips. Depending on your slicer, this takes about 750g filament.
The "hips" connect to the tree at about the base or 1-2 branches up from the base. The branches themselves can hook into the provided holes, or you can use green wire (bouquets), pipe cleaners, whatever.
Legs snap into the hips. Arms connect directly to branches. The head goes right on top like a star. Shape the tree and branches appropriately. Get some 2-3" elves from your favorite online retailer or at a craft store. Sharpie them up creatively. Hats are also fun, Rexy is in the spirit, of course.
Drew needed a wireless Tree-Rex, so he got a string of battery-powered lights and rewired the tree. His rexy is slurping up an elven boba drink!