Waterwraith

The Waterwraith, writes Olimar, "may be the ectoplasmic incarnation of a kind of psychic phenomenon". It is found only in Submerged Castle. Its appearance is generally humanoid in shape, with the suggestion of a head, body, arms, and legs, but without distinct characteristics, and with a watery, transparent body. The Waterwraith's name is a combination of water, given its watery appearance, and wraith, which means ghost or phantom.

Strategy
When encountered, the beast falls from the sky and moves around on its stone rollers. It will chase nearby Leaders and Pikmin, with a greater focus on crushing the active Leader. It is invincible to any Pikmin assault, even if it's petrified, except that of Purple Pikmin. When a Purple lands on or near the Waterwraith in a fashion that would stun any other beast, it turns a deep shade of purple not dissimilar to that of the Pikmin that cause this state to come about. Like this, it is vulnerable to all Pikmin attacks. When the Waterwraith's health has been fully depleted, the rollers crumble and it will scoot all around the cave, no longer a threat to your Pikmin. Attack with more Purples and then you can easily attack it with other Pikmin. When defeated, it will vanish into nothing, and you will be troubled no more.

Olimar's Notes

 * All that is known about this creature stems from a few sightings deep underground. All reported sightings feature the same core sets of details: a giant, viscous form with a clear, hazy sheen not unlike hard candy. One theory holds that it may be the ectoplasmic incarnation of a kind of physic phenomenon, but as is usually the case with such theories, it is very difficult to prove. All witnesses report being suddenly overcome with fear upon sighting the creature, approaching a state of panic and near insanity. In fact, every report an inordinate amount of extremely vague details, which has led to suspicion that exhaustion and fear have caused some simple natural phenomenon to be viewed as a living creature.

Louie's Notes

 * Inedible. Known to cause mass hysteria, followed by leg spasms and internal thunderings.

Pikmin:Redemption
The Waterwraith, along with the Firewraith, Electrowraith, Magneticwraith, and the Phantom, only appear in the Haunted Village, Crystal Palace, Tower of Babil, and Pit of Redemption. These creatures are extremely powerful and terrifying, but yield great rewards.

Pikmin 3 (Flish addition)
They reappear, along with several new forms of the same creature, but have a new attack. they can teleport like a Honeywisp and will fall from the ceiling again, falling on Pikmin. other members, which are faster, cannot do this. Black Pikmin are good to kill these, along with Purples, because even in their jell form Black Pikmin can injure them. This takes longer, however.

Pikmin: Dimensional Breach
Waterwraiths are mostly unchanged from their counterparts in past games, appearing in various late-game dungeons alongside other Wraiths, including its cousins from Pikmin: Redemption. Waterwraiths make up the bulk of Derrick's army. Black Pikmin cannot harm Wraiths by themselves in this game.

Sagittarius' Notes
 * This creature's horrific, ghostly visage and stone rollers mean it should probably be kept as far from civilization as possible.

Libra's Notes
 * This being is so evil, it doesn't even have the courtesy to leave behind anything to make clothes out of. Then again, I'm not sure I want anyone to wear... whatever this thing is made of.

Charlie's Notes
 * Only Purple Pikmin seem to be able to pierce this beast's otherworldly defenses. Throw one and the Wraith will be left cowering in this dimension and vulnerable to other attackers. If all else fails, don't be afraid to run. I fear no monster, but this... thing... It scares me.

Derrick's Notes
 * Draw a teardrop in a circle onto the ground, and place a basin of fine brass in the center of the rounded part of the teardrop. Fill the basin to the brim with water, taking care not to let any spill just yet. Now, you must find a sacrifice, an animal or person with a pure heart or an innocent mind. Take them over to the basin and drown them in it, keeping their face submerged until their skin grows cold, all the while chanting the ancient words of Lord Plasm. If done correctly, a Waterwraith should take its form from the spilled water, ready to wreak havoc on the world. Furnish it with weapons and equipment of your choice; I prefer the classic rollers carved from dense mountain rock.

Pikmin:The After Years
The Waterwraith is much stronger and appears along with the Firewraith, Electrowraith, Magneticwraith, and the two newly discovered Acidwraith and Clambering Wraith.

Pikmin 4
It reappears, along with the Firewraith, Electrowraith, Magnetwraith, Acidwraith, and the Clambering Wraith, although the entire family is weaker than their counterparts in other games.

Pikmin: The Winds of Light
The Waterwraith appears twice so far, both times in the Royal Wraith's Palace, once in the lower-right arena on Sublevel 2 and two of them appear in Round 5 of Sublevel 3. Also, in the Architect's Playground, hitting the wall on Sublevel 5 will trigger the sound of three Waterwraiths, yet none will appear.

Pikmin 4 (Wii U)
The Waterwraith appears in only two places, Ghost Den and Paradise Forest during nighttime. At Paradise Forest, two Waterwraiths appear at first and a larger one appears later on.