A Spill Proof Ceramic Travel Mug is incredibly hard to find. Most come with lids that claim to be spill or leak proof, but when you tip the cup, liquid always comes out.
The only way to make a tumbler immune to spilling or leaking is with a screw-on top. There are a lot of metal and some plastic models that feature those, but very few porcelain cups have a screwable lid. These two are the only ones that are any good.
Both are white with black writing or pictures. One is animal themed, the other is a joke cup. They are great for enjoying your coffee or tea on the road, just like you would with a thermos. The main drawback is the need to remove the lid to take a drink. But that’s the price you pay. Lids you can drink through also leak.
These are great options if you need to carry your cup in a bag or you have some other reason why you need it to not leak at all no matter what.