17 species carry Synchronize as a normal ability

Effect, in PokéAPI's words

“Copies burns, paralysis, and poison received onto the Pokémon that inflicted them.”

As a normal ability

Species	Slot	Note
Abra	Normal
Kadabra	Normal
Alakazam	Normal
Mew	Normal
Natu	Normal
Xatu	Normal
Espeon	Normal
Umbreon	Normal
Ralts	Normal
Kirlia	Normal
Gardevoir	Normal
Munna	Normal
Musharna	Normal
Elgyem	Normal
Beheeyem	Normal
Indeedee	Normal
Rabsca	Normal

Elsewhere in PokéAPI

1 more holder without a page here

Alternate forms and other species that PokéAPI lists with Synchronize.

Indeedee Female