Waterwraith

The Waterwraith, writes Olimar, "may be the ectoplasmic incarnation of a kind of psychic phenomenon". It is found only in Submerged Castle (all sublevels), and in Bully Den in Challenge Mode. 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. When encountered in the Submerged Castle, but not in the Bully Den, its music will play - music that is played only then. 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 Olimar and any Pikmin nearby, with greater focus on crushing the active Captain. It is invincible to any Pikmin assault, even if 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 Wraith's health has been fully depleted, the rollers crumble and the Waterwraith 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. It drops the Professional Noisemaker, a useful addition to the Exploration Kit the first time you beat it in the Submerged Castle.

Strangely, petrifying the Waterwraith makes it less vulnerable to Purple Pikmin, in which case the Pikmin must be thrown in a perfect arch for enough impact to make the creature susceptible to attack. In other words, Purples make a certain "squashing" sound when they hit an enemy or a plant; when this sound is performed, a creature may also be stunned. These effects can only occur when the Purples have a straight fall downward after their throw (the distance in which they fall vertically is irrelevant, as long as it exists). Finally, when all these circumstances are achieved, the Waterwraith may gain damage; this will not happen when Purples are thrown on it without the drop.

Note: In the Submerged Castle, you will only be able to get purples on the last sublevel (5) via the Violet Candypop Buds.

In the Bully Den, you will already have 25 purples, but no other color of Pikmin. Here, there are two Waterwraiths and a variety of other bugs.

The Waterwraith is one of the few enemies in Pikmin 2 which has its own background music, along with the Titan Dweevil and the Giant Breadbug. In Sublevels 1-4, when it appears, its own music track plays. When it has no rollers, a different piece of music plays, which has a more positive mood.

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 honeywhisp 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: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 Clamebring 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.

In 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, then a LARGER one appears later on.