Guts
Increases Attack to 1.5× with a major status ailment.
Full effect
Whenever this Pokémon is asleep, burned, paralyzed, or poisoned, it has 1.5× its Attack. This Pokémon is not affected by the usual Attack cut from a burn. This bonus does not count as a stat modifier.
In game description
It's so gutsy that having a status condition boosts the Pokémon's Attack stat.
Pokemon with Guts
#0019
Rattata
#0020
Raticate
#0066
Machop
#0067
Machoke
#0068
Machamp
#0136
Flareon
hidden
#0214
Heracross
#0217
Ursaring
#0236
Tyrogue
#0246
Larvitar
#0276
Taillow
#0277
Swellow
#0296
Makuhita
#0297
Hariyama
#0403
Shinx
hidden
#0404
Luxio
hidden
#0405
Luxray
hidden
#0532
Timburr
#0533
Gurdurr
#0534
Conkeldurr
#0538
Throh
#0862
Obstagoon
#0901
Ursaluna
#0931
Squawkabilly Green Plumage
hidden
Rattata
#0020
Raticate
#0066
Machop
#0067
Machoke
#0068
Machamp
#0136
Flareon
hidden
#0214
Heracross
#0217
Ursaring
#0236
Tyrogue
#0246
Larvitar
#0276
Taillow
#0277
Swellow
#0296
Makuhita
#0297
Hariyama
#0403
Shinx
hidden
#0404
Luxio
hidden
#0405
Luxray
hidden
#0532
Timburr
#0533
Gurdurr
#0534
Conkeldurr
#0538
Throh
#0862
Obstagoon
#0901
Ursaluna
#0931
Squawkabilly Green Plumage
hidden
Using Guts in Cobblemon
Abilities are passive and always active, so Guts 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.