I designed this life-size LEGO style mug. Inside it fits a quite common IKEA plastic cup that has a diameter of about 77 mm and a height of 85 mm. I'm not sure though if this specific cup is still a current product.
If you would like the mug to be adjusted to fit a slightly different sized cup, just send a comment and I'll upload another variant. Alternatively, simply scaling the the model a bit in your slicer software might do the trick, too.
LegoMug.stl | 2.1MB |