It's a brain. It's a bird-house. It's the brain birdhouse!
Print either as a single piece, or in two halves (for easier support material removal) then glue together.
Has a hole for birdies to enter, and a hook to hang from your tree of choice.
You could also hook it up with some LEDS and use indoors as a lamp.
We printed our example in 2 separate parts, and glued. We scaled up the file by 25X to create a brain birdhouse measuring 54 x 119 x 121mm once constructed. Each half took 7 hours approx to print, and used 114g of filament with the settings 0.20mm layer height, and 10% infill.