Sealnado, also known as the Twister, is a Boss Monster introduced in the Shipwrecked DLC. It spawns during the Hurricane Season. Before its arrival, wind noises will be heard and the characters will quote about an incoming Giant. It cannot be put to sleep with a Pan Flute or frozen with an Ice Staff, and is immune to fire. Sealnado receives 34 additional damage when attacked with a Cutlass Supreme. Defeating the boss in the Tornado form will drop Turbine Blades and reveal its Seal form.
If the player refuses to kill the Sealnado in its seal form, it will disappear once the player leaves the approximate vicinity of the seal. When it disappears, it will leave behind a Magic Seal. This choice allows obtaining the Magic Seal without having to face Krampus; however, the Meat reward will be unobtainable.
The Sealnado generally has two patterns: punch and twister. Initially, the Sealnado twister AoE attack can be done as one of the first couple attacks during encounter. Sealnado will throw about 3-6 Sealnado punches between each twister attack.
Sealnado will absorb nearby items continuously. However, it will drop a few when attacked.
Sealnado will create a large twister AoE attack around its area. On land, the twister sucks up the player, causes 250 damage, drains 33 sanity, and absorbs a couple of the player's items. On the Ocean, Sealnado's twister will instead draw in Common Waves inward, and then releases Big Waves outward.
Sealnado will try to go off-screen to despawn once Monsoon season arrives.
It is not recommended to fight the Sealnado near a base if the player has Walls and Sandbags, as certain attacks will quickly decimate them. The fight is considerably easier on land, so its recommended to fight this way.
Fighting on land
The basic strategy is to hit the Sealnado 2-3 times and dodge. When the Sealnado performs its twister attack, the player has less than 5 seconds to get away. A safe distance includes the Sealnado off of the screen plus slightly more. Wearing windproof items like Windbreaker allows players to be somewhat closer to Sealnado without being sucked in.
After 2-3 player attacks, the Sealnado will motion one of its arm to land a punch. The player can tell the twister casting is finished when a thunder sound is heard from the distance or by viewing the outer edge of the screen, where the whirl twister will start disappearing.
Walls can be used to protect against the twister by hiding behind them. These walls will still work even if they are flattened.
Fighting in the ocean
The Sealnado's attack timings are the same over the ocean. However, the twister attack will now create waves instead of sucking in the player when on a boat. The Sealnado draws small moving Waves inwards about three times. This is followed by large waves that radiate away from the Sealnado. Damage from the waves can be avoided entirely for 30 seconds by eating a Purple Grouper or a Tropical Bouillabaisse.
- The wind noises can be hard to identify during Strong Winds, making the character quotes the only way to detect Sealnado's approach, therefore Characters that cannot speak are at a disadvantage.
- As with any other Mob, naughtiness only applies when the player directly makes the killing blow. Therefore the seal can be killed with help of other Mobs (which may eat Meats), fire (which will cause cooked Meats to drop instead), or Poison (which will cause Meats to be stale) to avoid Krampus while still getting the Meat.
- The player can stand behind stationary objects when Sealnado starts the tornado and will not be sucked in or take damage. Stationary objects include flattened walls.
- The Sealnado attacks can remove equipped weapons but not armor.
- The player can ride a boat when Sealnado starts the tornado and will not be sucked in or take damage.
- Luring Sealnado near a few Dragoon Dens during daytime can easily kill it.
- Water Beefalo will target Sealnado, potentially leaving the defenseless seal form which the player can then kill or spare. However, it should be noted that Sealnado is capable of completely taking down small herds, so caution is advised.
- Sealnado will attempt to flee when Hurricane Season ends, even if in combat. If Sealnado successfully flees, he will despawn.
- Walani is a good choice for fighting Sealnado on her surfboard.
- The Sealnado was introduced in the Wilbur Vs. The Volcano update.
- The Sealnado, along with Ancient Guardian, Spider Queen and (Palm) Treeguards are the only Boss Monsters in the singleplayer game that are not a mix of two living creatures.
- It is possible that the Sealnado is the cause of the weather changes in Hurricane season, as when the Sealnado is out of its tornado form, all weather affects end till the season is over.
- The name "Sealnado" is a portmanteau of the words "Seal" and "Tornado".
- The Sealnado may also be a reference to the movie Sharknado.
- The Sealnado shares several characteristics with Deerclops, such as spawning during Winter/Hurricane Season, being more dangerous than other bosses towards player structures, and sharing the same melee attack period, attack range, and damage towards a player.
- If the Sealnado absorbs and drops many meat food items in the water, eventually, massive amounts of Sea Hounds and Crocodogs will be summoned until the Sealnado is killed.
- It's possible that the Seal managed to form and envelop itself in the tornado thanks to the Turbine Blades and its magic; this is suggested and supported by the fact that he drops the item when the tornado spreads out once defeated.
- If the Sealnado sucks up any items, including special items like the Fishbone, and then despawns when Hurricane season ends any items sucked up will be lost forever.
- If attempting to craft something while caught inside the Sealnado, the character will disappear and be unable to move or interact with their inventory or the environment.
- Sometimes when fighting the Sealnado, it will randomly lose interest in the player, and will not fight back even if the player continuously hits it.
- If the Sealnado begins its AoE attack in the exact moment it is killed, the player will be stuck floating in the air and unable to move. Reloading the game or getting attacked by Charlie fixes this issue.