Heavy Metal
Doubles the Pokémon's weight.
Full effect
This Pokémon has double the usual weight for its species.
In game description
Doubles the Pokémon's weight.
Pokemon with Heavy Metal
Using Heavy Metal in Cobblemon
Abilities are passive and always active, so Heavy Metal costs you nothing to run. If it is marked hidden on a species above, expect it to be harder to obtain: 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.