Ferrothorn

Grass

Ferrothorn is a staple pick on Grass teams due to its great natural bulk and fantastic defensive typing, giving it an immunity to Poison-type attacks. Iron Barbs alongside its great natural physical bulk allows it to act as a blanket check to a variety of physical attackers such as Excadrill and punish contact move users such as Alolan Muk and Metagross. Ferrothorn is also blessed with fantastic utility moves in Leech Seed and Spikes; the former allows it to have a form of passive recovery, while the latter allows it to support its offensive teammates by chipping their checks. However, while its Steel typing does offer plenty of defensive utility, it also exacerbates its natural Fire weakness, and with all these amazing qualities, Ferrothorn also has a decent number of drawbacks such as its low Speed stat, which allows it to be easily broken by Taunt users such as Mew, Gliscor, and Hydreigon. Ferrothorn also is held back by the fact that it is dependent on passive forms of recovery such as Leech Seed and Leftovers to stay healthy throughout the match.

Steel

Ferrothorn is one of the best defensive Pokemon on Steel teams thanks to its excellent typing and mixed bulk making it an excellent defensive pivot. Its Grass typing makes it a great addition to Steel teams, as it's able to check Ground- and Water-types such as Swampert, Gastrodon, and Seismitoad and resists Electric- and Water-type attacks. Its ability Iron Barbs lets it wear down physical attackers upon contact and potentially break their Focus Sashes and Sturdy, and its great movepool including Spikes, Stealth Rock, Leech Seed, and Knock Off allows Ferrothorn to provide support and utility for its teammates. Unfortunately, Ferrothorn lacks any type of recovery move outside of Leech Seed, which makes it easy to wear down. Its offensive presence isn't that great either, and it mainly utilizes two attacking moves in Power Whip and Knock Off, making Ferrothorn vulnerable to Taunt and potentially setup bait for sweepers. Ferrothorn also lacks Speed, being outpaced by almost the entire metagame. Ferrothorn is vulnerable to Fire-type attacks, which means that it has to rely on Protect to scout the opposing Pokemon's coverage or switch out to a check like Heatran.