Only water, grass, and ice. (Hippowdon is one of the few Pokemon I can think of that are only Ground types.)
Hippowdon is a Ground-type Pokémon and is weak against Water, Grass and Ice.
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
Steel is super effective against rock type pokemon.
Rock, electric, ice, and psychic types are super effective against Crobat.
Flying and Psychic are super effective against fighting
Lightning is super effective against water. I hope this helps.
Hippowdon is a Ground-type Pokémon and is weak against Water, Grass and Ice.
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
Hippowdon is a Ground-type Pokémon, which makes it particularly weak to Water, Grass, and Ice-type moves. Using Pokémon that have strong Water, Grass, or Ice-type attacks will deal super effective damage against it. For example, moves like Surf, Giga Drain, or Ice Beam can exploit its weaknesses effectively in battle. Additionally, Pokémon like Gardevoir or Ludicolo can be good choices due to their access to these types of moves.
Bug Type and Fighting Type moves are super effective against it.
Steel is super effective against rock type pokemon.
Rock, electric, ice, and psychic types are super effective against Crobat.
super effective is bug
psychic pokemons and attacks are super effective
Bug types are super effective against Dark, Grass and Psychic (x2) in Generation II-onward. In Generation I, they were super effective against Grass, Poison and Psychic.