3 species have Healer as a hidden ability, 7 as a normal one

Effect, in PokéAPI's words

“Has a 30% chance of curing each adjacent ally of any major status ailment after each turn.”

As a hidden ability

Species	Slot	Note
Chansey	Hidden	Since Generation V
Bellossom	Hidden	Since Generation V
Blissey	Hidden	Since Generation V

As a normal ability

Species	Slot	Note
Audino	Normal
Alomomola	Normal
Spritzee	Normal
Aromatisse	Normal
Hatenna	Normal
Hattrem	Normal
Hatterene	Normal

Elsewhere in PokéAPI

2 more holders without a page here

Alternate forms and other species that PokéAPI lists with Healer.

Audino Mega, Hatterene Gmax