Imagine someone receiving this mug full of tea, not knowing about the eyes until they tilt the mug to take a sip.

Two sentence horror

And not knowing that there's a whole frog under them until they take a couple more 😄

i want this

But tea isn't opaque...

There's a type of mug that was a popular joke in the Victorian era where there's a frog at the bottom of the mug, and it's hollow underneath, so that it makes a bloop noise when you've drank enough tea.

Is this food safe?

It looks glazed, so yes.
Ceramics are fired at 900-1000°C then glazed and fired again at 1300°C. If it's not specifically a crackle glaze or something to that effect, the glazed surface is basically like glass.

Hear me out.

A battery powered, coffee cup sized one of these:

I'm listening!

But how do you scrub all those nooks?

Just spray it out when done - it's not that hard

I have one that reveals itself as you get close to the end of your drink.

the bacteria 😅

Maybe I’m stupid and speculating on this accurately isn’t in my wheelhouse but that frog looks awfully lumpy and whatever glazing it has looks spotty at best, without a good shine to it. I personally wouldn’t want to use a mug of this quality for fear of food safety, regardless of what you’ve said.

As much fun as a frog in a glass of milk. The world according to Bob Weir.

The tea in the OP looks reasonably opaque. It's probably a darker English tea with a substantial amount of milk, as opposed to a lighter Asian green tea.