Tastyx

Tasty.
Styx.
Tastyx.

It might be delicious, but it's probably best to avoid drinking from the river that brings you to the underworld, unless you're literally dying of thirst and you'll end up there anyway.

Hades.
Desperate.
Hadesperate.

Achilles got dunked in the river, and see what eventually happened to him...

Achilles.
Lesson.
Achillesson.

So, if you must drink river water, try one that doesn't border the land of the dead.

Mississippi.
Sippy-cup.
Mississippy-cup.