Bug, ghost, and dark types are most effective against psychic types.
super effective is bug
Ground type is super effective against electric, fire and rock type Pokémon.
Ground-types are super effective against electric-type Pokémon.
Actually the Ground is the only super effective type against thunder type pokemon.
ground type Pokemon are super effective against poison type Pokemon.
super effective is bug
Ghost, dark and bug type moves.
Ground and bug types.
Bug Type and Fighting Type moves are super effective against it.
Ground type is super effective against electric, fire and rock type Pokémon.
Ground type and psycic type
normal type Pokemon are not super effective against any type.
Ground-types are super effective against electric-type Pokémon.
Actually the Ground is the only super effective type against thunder type pokemon.
ground type Pokemon are super effective against poison type Pokemon.
Rock, electric and ice are super effective against flying type pokemon.
The Psychic-type is very weak against the Dark-type such as houndour murkrow tyranitar...Pokemon.marriland.com is a great reference. He plays them all and is playing Heart Gold or Soul Silver now probably.