Level 100 Statistics (see level 5, 50, 100)
Don't be fooled by Clamperl's baby face and charms; she's one of the most deadly Pokemon in UU. DeepSeaTooth doubles her Special Attack stat, giving her more immediate power than even the feared Deoxys-A. However, without her signature item, Clamperl is essentially useless. Clamperl also has awful Speed, making Trick Room a necessity to her success. If you can provide adequate support for her, Clamperl will be a dangerous addition to your team.
Although Clamperl is slow and frail, she hits like a truck. When Trick Room is in effect, Clamperl becomes one of the fastest Pokemon in the game. Additionally, Her Water-typing gives her a resistance to many common priority moves, such as Ice Shard, Bullet Punch, and Aqua Jet, making her the ideal Trick Room abuser. DeepSeaTooth doubles Clamperl's Special Attack to an insane 542, turning her into a dangerous threat when used correctly. Surf provides reliable STAB, Ice Beam hits Grass-types, and Hidden Power Grass is for rival Water-types, like Quagsire and Milotic. Finally, Brine deals more damage to weakened opponents, which is especially helpful against Chansey and Registeel, while Toxic cripples defensive Pokemon who are difficult to get past. Keep in mind that when using Clamperl, it is very important that you switch her in unscathed, as her defenses are very low.
Team Options & Additional Comments >>>
Clamperl has a very limited movepool, giving her few options to play with. DeepSeaScale can be used on a defensive set, along with Toxic and Protect to stall, though Pokemon such as Milotic do this much better thanks to their reliable recovery moves and much higher HP stats. Substitute may be used on a switch to ease prediction, though if Trick Room is in effect, this will waste a valuable turn.
Checks and Counters
Pokemon with high Special Defense are the best counters, taking reduced damage from Clamperl's attacks and having a way to stall or retaliate. Chansey, Clefable, and Registeel are good choices, with all of them having access to some form of recovery (in Registeel's case, using Rest to recover damage), while hitting Clamperl with Seismic Toss or Earthquake. Bulky Water-types also do a decent job, as they don't take much damage from Surf or Ice Beam, and usually carry a super effective Hidden Power that will KO Clamperl. Just be careful about switching into Hidden Power Grass, as most bulky Water-types can be 2HKOed by it. Ludicolo is a lesser-used counter, though he can switch into Surf and Hidden Power thanks to his handy resistances, and takes less damage from Ice Beam due to his high Special Defense. Provided you can switch in safely, priority moves will be deadly towards Clamperl. Arcanine can switch into Ice Beam or Hidden Power Grass and hit Clamperl with ExtremeSpeed, while Spiritomb does a fine job with Sucker Punch and his good defensive stats. Finally, Clamperl is useless without her signature item, so Knock Off, Trick, and Switcheroo users utterly destroy Clamperl.