- The wielder's stats cannot be lowered.
- Leeching moves cause the enemy to lose HP instead.
- Heals 1/16 maximum HP in rain.
Level 100 Statistics (see level 5, 50, 100)
Tentacruel was a bit on the fence last generation in regard to viability in the Uber tier. This generation has been kinder, granting it a few traits that make it quite useful and provide it with longevity. Rain Dish is a great boon, and it doubles Tentacruel's recovery per turn (assuming rain is up, of course). Tentacruel also boasts both Toxic Spikes and Rapid Spin, two much sought-after moves in the Uber tier. The jellyfish also has quite good synergy with both Giratina-O and Ferrothorn, which can both help Tentacruel in various ways. Unfortunately, Tentacruel has rather poor physical bulk, and will fall easily to Earthquake and other physical attacks. Although 12.5% recovery per turn is nothing to laugh at, Tentacruel still lacks the staying power Pokemon such as Ferrothorn have against powerhouses, and the lack of significant recovery will usually catch up to it eventually. However, do not let these disadvantages deter you from thinking Tentacruel can be one annoying little jellyfish.
As previously mentioned, Tentacruel is one of the few viable users of Toxic Spikes and Rapid Spin in the Uber tier. Do not make the mistake of thinking this Pokemon is inferior to Forretress; Tentacruel has several qualities that let it hold its ground against threats the bagworm might fall to. First off, Tentacruel has much greater special bulk, and, in comparison to Forretress's physical bulk, is more desirable in Ubers. Tentacruel also gained Scald this generation, which can burn any would-be physical threat and make it useless (unless the opponent packs a cleric). Scald also has respectable power in the rain after a STAB boost. Tentacruel was given Rain Dish in the generation shift as well, which, in tandem with Black Sludge, gives it 12.5% recovery per turn, which is nothing to scoff at. This jellyfish also has a surprising base 100 Speed, meaning it will often outspeed Pokemon such as Groudon and Dialga, which don't do much other than creep base 90 Speed Pokemon by a few EVs.
The first two moves are obvious—Toxic Spikes and Rapid Spin give Tentacruel its niche. Scald is a solid choice in the third slot, and can turn would-be counters into useless burned husks. However, if you wish, you can swap out Scald for one the of moves slashed in the fourth slot. The last slot is a bit trickier. Ice Beam allows you to put a respectable-sized dent in the Dragon-type Pokemon which run rampant in the Uber tier, and, more importantly, Giratina-O, though it can't do much to touch Tentacruel outside of the rare Earthquake, Outrage, or Thunder. The 32 Defense EVs prevent a max Attack Giratina-O with an Attack-boosting nature from OHKOing a full HP Tentacruel with Earthquake. Dragon Tail can annoy Tentacruel a bit, but it will quickly recover from minor hits through Rain Dish and Black Sludge. Protect is also a decent choice, allowing Tentacruel to maximize its Rain Dish and Black Sludge recovery; however, it can be risky. If you aren't careful, Protect can provide the opponent with free switches and turns to set up. Don't ignore this option though, since it can allow Tentacruel to accomplish impressive feats such as survive the 2HKO from unboosted Thunder off 150 SpA (it maxes at 61.5% with the given EV spread). Protect also causes the opponent to take a bit more damage from poison, burning a turn before you are forced to switch to a check.
Team Options & Additional Comments >>>
Magic Coat is an interesting option to reflect moves such as Ferrothorn's Leech Seed and Darkrai's Dark Void, but it is a novelty at best. Liquid Ooze is also usable to annoy Ferrothorn, but its usefulness stops there, and Tentacruel will sorely miss Rain Dish. Confuse Ray can be used to annoy opponents, but it isn't very reliable. Icy Wind can slow down opponents, but Ice Beam is a far superior choice in almost every scenario, due to its higher Base Power. Giga Drain can be used to milk every last option of recovery Tentacruel has short of Rest, but it really isn't worth it and does rather poor damage. Finally, a Stallrein-esque set with Protect, Substitute, Toxic Spikes, and Scald in tandem with Rain Dish and Leftovers can be quite annoying, but, unfortunately, rain doesn't have the damaging quality that hail does, so it is a bit less effective. Still, it is not something to be taken lightly with Tentacruel's impressive Speed.
Checks and Counters
Groudon is Tentacruel's #1 enemy. It takes away the rain Tentacruel loves so much and can OHKO Tentacruel with Earthquake, even with 0 Atk EVs, unless you invest significantly in Defense. Groudon can also incinerate Tentacruel's most commonly used partner, Ferrothorn, with Fire Punch. It does have to watch out for burns, though, and Toxic Spikes + repeated attacks will wear it down quickly. Tentacruel crumples to powerful attacks in general—it should be played as a tank, not a wall, lest you let its lack of a reliable recovery move catch up to it. Physical attackers in particular can easily wear Tentacruel down due to its poor Defense stat. From the special side, Palkia, Kyogre, and Dialga all receive special mention. Tentacruel really can't touch the former two no matter what attack it runs, although they must be careful of Toxic Spikes or they will quickly succumb to poison. Dialga, however, is immune to Toxic. All three of these Pokemon are commonly seen with Thunder, and although Tentacruel is not 2HKOed by a non-boosted Thunder, it certainly won't like taking one. Mewtwo can easily shatter Tentacruel with Psystrike, but once again Toxic Spikes and its usual Life Orb will wear it down quickly. Giratina-O can block Tentacruel's Rapid Spin and pose a threat with Thunder or Earthquake, although neither can ever OHKO a full HP Tentacruel, and the former can even fail to 3HKO (although that requires near-minimum damage rolls every time). Giratina-O also will not like Ice Beam very much. Manaphy can set up on Tentacruel with ease and ignore Toxic Spikes with Hydration. Almost any Arceus with Refresh and a boosting move can easily set up on Tentacruel. Poison Arceus in particular can be a nuisance simply for the fact that you cannot see it on team preview and it can nullify the turns you spent setting up Toxic Spikes simply by switching in. Ground Arceus can also OHKO Tentacruel, but it cannot switch in easily for fear of Scald and a burn. Ho-Oh can't be burned and isn't even 2HKOed by Scald in the rain, and can threaten Tentacruel with powerful physical attacks. Zekrom is another physical attacker which gives Tentacruel a run for its money with STAB Electric-type attacks, which can OHKO with ease, but Zekrom won't appreciate a burn so it must be careful. Finally, Giratina can annoy Tentacruel with Will-O-Wisp and Dragon Tail, and later Rest off the poison inflicted by Toxic Spikes.