I bought one of each of these hidden animal mugs in the series (bear, fox, owl). The description states they hold 2 cups each. In my experience, this is wrong. The fox cup (with a buffer of about 1/2 inch from the very top of the cup) will hold about 2 & 1/4 cups. I usually make tea for 1 - 1 & 1/2 cups at a time.. this is not enough liquid to fully cover the fox, so you have to be willing to drink more liquid if you want the full "hidden fox" effect (no hidden fox for me, just one taking a nice, hot bath with head above water). The sizes are actually different for all the animals. The fox is the largest, while the owl is the middle size (good for about 2 cups). The bear cup is smallest (good for about 1 & 1/2 cups).
All the cups have a hole in the bottom of the cup (probably required puncture for the firing process of the ceramic - apparently the ceramic animal is hollow). There is no leak of the actual beverage from the cup through this hole because the animal is sealed securely to the inside of the cup, BUT if you use the dishwasher to wash these cups and place them upside down in the washer (obviously), you might get water that enters into that cavity between the underside of the cup and the inside of the animal through that small hole puncture in the bottom. Then, when you flip the cup over and use it to drink, you might (as I do regularly) get "leaking" out of the water that crept in there during dishwashing. At least it's basically clean water, but this is a minor irritation since it's inevitable I will find a small puddle on the table from this. If I wash by hand, I don't get water in the cavity because I don't let the water run over the hole in the bottom while rinsing it since I can control it better, but when I wash by hand, I don't get as good a clean cup since there are several tight crevices in the sculpted animal that resist being touched by a sponge as you try to rub it all over. Thus the trade-off I go back and forth between every time I have to wash this cup.. do I want an extra clean cup today or do I not want to deal with a puddle on the table.
That said, these cups are very cute and I still love using them. I wish they were more uniform in size since it's not always easy to remember what level to fill to on each cup to get the same amount of beverage in each one when I'm serving different people since the cups are all different sizes. Even empty, the cup has quite a bit of weight to it. Filled with liquid, it can get to feeling heavy pretty quickly, so I wouldn't recommend this as a child's cup.