Ferrothorn

Ferrothorn has a lot to love as a defensive Pokemon. First and foremost, it has a great Grass / Steel typing and solid mixed bulk. Together, its unique set of resistances and bulk allow Ferrothorn to check a plethora of threats. In addition to this, Ferrothorn has access to a wide array of support moves, such as Stealth Rock, Spikes, Leech Seed, and Thunder Wave. Because it has decent offensive presence, Ferrothorn can be hard to switch into for many offensively-oriented teams. However, while Ferrothorn's typing gives it a great set of resistances, it also gives it a glaring 4x weakness to Fire-type attacks, which means that Ferrothorn is easily forced out by Fire-type opponents. In addition to this, some special attackers, such as Latios, can get past Ferrothorn if they are carrying Hidden Power Fire. Ferrothorn's typing also leaves it vulnerable to being trapped by the increasingly common Magnezone. Lastly, Ferrothorn's Speed is terrible, which means it has to rely on surviving an attack before using a move itself.