5 species have Poison Touch as a hidden ability, 4 as a normal one

Effect, in PokéAPI's words

“Has a 30% chance of poisoning target Pokémon upon contact.”

As a hidden ability

Species	Slot	Note
Grimer	Hidden	Since Generation V
Muk	Hidden	Since Generation V
Croagunk	Hidden	Since Generation V
Toxicroak	Hidden	Since Generation V
Sneasler	Hidden

As a normal ability

Species	Slot	Note
Seismitoad	Normal
Skrelp	Normal
Dragalge	Normal
Grafaiai	Normal

Elsewhere in PokéAPI

2 more holders without a page here

Alternate forms and other species that PokéAPI lists with Poison Touch.

Grimer Alola, Muk Alola