Decadent

The “Grenouille Congelée” is just an ordinary martini with an ice cube.
And inside that ice cube is a frog.
The ice cube is hollow, giving the frog a little room to move around.
It doesn’t move much. Frogs are cold-blooded and they hibernate at low temperatures, so if it moves at all, it’s going to be a groggy frog.
The cube melts easily.
Once the ice melts, the frog wakes up, and it crawls out of the glass.
An empty glass, usually, but if you’re slow to finish your drink, you may be in for a small green surprise.