Synchronize
If another Pokemon burns/poisons/paralyzes this Pokemon, it also gets that status.
Pokemon with Synchronize
Using Synchronize in Cobblemon
Abilities take effect when their particular conditions are met. If Synchronize is marked hidden on a species above, its availability depends on the server: servers differ in whether hidden abilities come from breeding, an Ability Patch, or events.
See the Pokedex for which abilities each species can have, and IVs, EVs and breeding for how to actually pass one down.
Battle summaries use the Pokemon Showdown Generation 9 reference. Species associations come from PokeAPI. Custom server mechanics and mod versions may differ.