Print the Oddball.stl twice with the flat side down and two Oddball_Merger.stl.
For best results, use a layer height lower than 0.2mm, even though 0.2 works as well.
No support required.
Use a little superglue to put the two halves together and you're good to go.
Tested with PLA and TPU 95A.
The author marked this model as their own original creation.