There's whatever Honest John was drinking in An American Tail. Seems to do nothing to him but get him drunk, but it does burn holes in the floorboards.
In The Rescuers, Luke the muskrat is always toting a jug of "swamp juice" which he charitably gives to anyone who looks a little tired ("It's good for what ails ya."), leaving the poor drinker with fire and smoke coming out of his mouth. That, and it gives the dragonfly, Evinrude, a burst of energy — and is used for fuel in a jetski-like vehicle.
On Monsters vs. Aliens, Dr. Cockroach offers Susan's folks some "atomic gin fizz". It explodes as he's mixing it. Lord knows what would have happened to the poor soul who would ingest it.
In The Emperor's New Groove, Kronk is mixing up Yzma's poison for Kuzco at dinner. As he proceeds to add in the poison, a horrifying pink explosion explodes out of the cup.
Cactus juice in Rango. A fly drinks it and keels over... and then one of its eyes pops out. It also made Rango breathe fire (after eating a lit cigar).
In a flashback in Despicable Me 2, El Macho makes himself a cocktail of rattlesnake venom and something called "La Venganza de Escorpión" ("Scorpion's Revenge"), then eats his drink, glass and all.