It's a mug. It's a brain. It's a brain mug.
For obvious liability reasons, you're on your own putting hot liquids into whatever plastic you're trying to print with, but the geometry itself should be both watertight and water tight.
I'll save you the effort of checking: it's $105 from Shapeways to have it printed in dishwasher safe ceramic. Maybe you're a money bags, but that's too much for a mug in my mind, so I'm throwing the model here for fun.
To be honest, the mesh is a little janky. Tried my best to remesh it to eliminate the disgusting huge poly count that was on the inside of the walls from how the tubes generated, but there's still little bubbles I can't get out - you'll see them if you run a slicer preview.
That said, barring some time inefficiency printing small inside details, it should print okay overall.
Measured my mug -> Fusion 360 model -> Houdini growth generator -> a colleague had Zbrush and remeshed it for me because Blender, Houdini and Meshmixer all did a very bad job of it.