When introduced in GSC, Crobat was immediately relegated to UU, due to having subpar stats and a relatively small movepool. Sadly, not much has changed, and once again Crobat sits in the UU tier. However, there is some light at then end of the tunnel for everyone's favorite cave dweller. Crobat's unique typing grants it a 4x resistance to Fighting-type attacks, one of the most common in the tier, and in conjunction with its blistering Speed, this gives Crobat a useful niche in the OU metagame. Crobat can also utilize Taunt and a relatively exclusive move in Super Fang to easily break down the major part of most stall teams, while STAB Brave Bird gives it the ability to be an effective check against most offensive teams.
However, a crippling Stealth Rock weakness and below-average offensive stats mean that Crobat is often outclassed by other Pokemon, and it will often find itself fighting for a team slot. On the whole, if you want to utilize Crobat on your team, make sure that you play it to its strengths, because otherwise, you will find that it is outclassed by other Flying-types, such as Aerodactyl.
With Crobat's blazing Speed and resistance to Fighting-type moves, along with a valuable Ground-type immunity, it can quite effectively come in on Choice-locked attacks, Taunt the opponent, and proceed to wreak havoc with a combination of Super Fang and Brave Bird. This set is effective as the majority of defensive Pokemon that try to wall Crobat are crippled by Taunt and Super Fang, while not many offensive Pokemon will like taking a STAB Brave Bird.
Taunt is the main move of the set, and it is practically the only reason to use Crobat in OU. With Taunt and Roost, Crobat can continuously recover in the face of defensive Pokemon while wearing them down with Super Fang and Brave Bird. The remaining moves on the set are to give Crobat some offensive prowess. Brave Bird is used as a general STAB move, which still hits hard despite Crobat's mediocre base 90 Attack stat. Finally, Super Fang is used in the last slot to bring down Pokemon into the KO range of Brave Bird; this is a very effective tactic, as only Ghost-types are immune to Super Fang, most of which will take a large amount of damage from Brave Bird.Team Options & Additional Comments >>>
Unfortunately, Crobat is not one of those Pokemon that can boast a plethora of other options, as most of the other sets that it could possibly run are mostly outclassed. Crobat can run a Nasty Plot set, but its awful special movepool and middling Special Attack stat mean that other stronger special attackers such as Starmie work to a better effect. Toxic is effective on any of Crobat's sets, and as such, it should always be considered. Finally, a Choice Band set can make an effective revenge killer with Brave Bird, but on the whole, it is outclassed by Choice Scarf Staraptor, who can perform the same role with better coverage moves and more power thanks to Reckless.
Checks and Counters
Since Crobat is relatively frail, it is easy to take out with a super effective hit. Any Pokemon that doesn't mind Taunt can easily eliminate Crobat with a super effective attack. Rotom-W is also a solid check, as it can easily OHKO Crobat with STAB Thunderbolt, while recovering off any damage taken from Super Fang later with Pain Split. Gengar is a fantastic check to Crobat, as it is immune to both Super Fang and Toxic, doesn't particularly mind Taunt, and can hit back hard with Shadow Ball. Finally, most Steel-types can easily wall Crobat, thanks to their resistance to Brave Bird. If they can hit back hard, then Crobat is almost certainly going to be forced out. It is important to remember that when wanting to counter Crobat, you must utilize Stealth Rock, as most of the time, Crobat will take any opportunity to switch out of danger with glee, and as such, it is important to put a tax on its excessive switching.