induration. 1. the process of hardening or being hardened.
1 They're weak against the Ice and Water types in reference of erosion, which cause this elements to the ground. 2  They're immune against the Electric type because in real life, the ground is a natural sink of electrons.  The Bug type resists them because many bugs like worms live inside the ground and many of them eat it.
Best Answer: Drapion is weak to Ground-type attacks because that is one of the only weaknesses that Poison-type Pokemon have besides Psychic-type attacks. Other than that, I am drawing blanks as to what else Drapion could be weak against. Source(s): Own experience.