Zubat

Zubat has a 4x resistance to Grass-, Bug-, and Fighting-type attacks, as well as an immunity to Ground-type attacks. It also has access to Brave Bird, which hits most of those types super effectively. Zubat has access to Infiltrator, which allows it to attack through Substitutes, and it gets Defog, which clears away all entry hazards and screens on the field. With these resistances and abilities, Zubat works well as a support Pokemon. However, Zubat's subpar stats keep it from being able to take advantage of these good traits. Zubat has several good special moves, but it has a terrible Special Attack stat to back them up and it lacks good physical attacking moves. Zubat only hits 16 Speed, which means that it is outsped by many common threats such as Mienfoo, Archen, Trubbish, and Drilbur. Its pitiful defenses make it hard to use for extended periods of time, and its Stealth Rock weakness makes it hard to switch in, which it should be doing a lot.