Phantamanta

Phantamanta is a boss in Super Mario Sunshine and is also the cause of the dissappearance of Hotel Delfino. It appears in the first episode of Sirena Beach, The Manta Storm. It is a pale pink silhouette of a manta ray. When hit by water from F.L.U.D.D, it splits into smaller versions of itself.

Wherever Phantamanta moves, it leaves a trail of green and yellow electric goop. If there is even a tiny drop of it left, Mario can get shocked when he touches it. The only area where the Phantamanta cannot reach Mario is if Mario is under one of two huts. The Manta first divides into two. Each of those Mantas can divide into two more. Each of those divide into four Mantas. And, each of those can further divide into four more Mantas, making a total of 64 Mantas to defeat. When all of the Mantas have divided fully, they will turn purple and start swarming towards Mario. Once the last one is vanquished, Hotel Delfino will be restored, revealing a Shine Sprite for Mario to collect.

It may be related to Manta.

Trivia

 * Phantamanta's music is a remix to the normal Boss music.
 * In Mario Golf: Toadstool Tour, a name on the scoreboards is Phantamanta.
 * The 64 Mantas the player has to defeat may actually be a reference to Super Mario 64.
 * The largest form of Phantamanta actually does pursue Mario, even when not colored purple.