I got this idea more than a year ago but was unable at the time to realize it due to lack of skill. This is a mug based upon a real human skull to have the sensation of drinking out of the skull of your enemies >:) . I filled all holes for it to be waterproof and tried at maximum to keep all the natural features of the skull.
This mug can contain about 800mL of liquid but is a bit oddly shaped. You can obtain a handleless version of this by splitting the model into its parts, would you want to use it as a (candy) bowl, for example.
Due to the odd shape of the skull the handle is a bit tight, but does the trick. Would you scale the mug down however you probably won't be able to put all your fingers through it.
Printing information:
It is important to note that the 3d printing process is not necessarly food safe even if the printing material used is labeled as such, therefore it is recommended to coat any 3d print which comes in contact with food, mouths, … with for example a food safe epoxy resin. This can also be an additional way to make the model waterproof.
The author remixed this model.
I cut the top of the skull, filled all its holes to make it waterproof and scaled it. I then added the handle onto it.