Williwaw

Williwaw is one of the three bosses added in the Neapolitan update and is found in the Glacier.

Behaviour
Phase 1


 * Williwaw takes the form of an icicle embedded in the middle of the room, that starts to tremble and pull in many snowflakes that are immune to damage, healing himself up to full health over time.

Phase 2(starts at 100% health):


 * Williwaw starts chewing something, then faces appear on his cheeks and he spits. This fires 3 large shots that deal a full heart of damage that spin around Williwaw and stop in place. These also trail smaller shots. One by one, each string of shots will be fired in an arc roughly towards the player, with the large shot splitting into several smaller shots.
 * Williwaw flies upwards then darkens and becomes electrified. He then dashes downward, leaving freeze auras and shots that will be fired at the player after a short delay. He then repeats this, moving up instead of down.
 * Williwaw flies towards the left or right edge of the room and starts blowing, freezing the player. He moves up and down near the edge of the room while snowflakes are blown either left or right in patterns. After a while, Williwaw will cough up a Grill o' Wisp and a wall of snowflakes that must be killed. During this attack, a blizzard visual effect will appear on the screen.

Phase 3(starts at under 66% health):


 * A piece of ice will fall on the icicle inside Williwaw, cracking it. This causes Williwaw to fire shots in the cardinal and diagonal directions. This attack only happens once, at the start of the phase.
 * Williwaw will then spawn a clone that is immune to damage, but only has phase 2 attacks.
 * The icicle inside Williwaw will flash red and then fire up into the sky, spawning 6 orbiting snowflakes that follow the player. Eventually, the icicle crashes down, killing the snowflakes if any are still alive.

Phase 4(starts at under 33% health):


 * Williwaw will spawn 4 more clones. The clones and Williwaw will all now have new behaviour, entirely different from earlier phases.
 * Both the clones and Williwaw will circle around the player rapidly. If they have to move through the player to make a complete circle, they will fade out and not deal contact damage.
 * Williwaw will fire a slow, large shot at the player which deals a full heart of damage.
 * Occasionally, Williwaw will swap places with a clone.
 * Both the clones and Williwaw will slow down, then the icicle inside Williwaw will flash red and shoot into the sky. While it is in the sky, snowflakes will orbit the area where Williwaw used to be.
 * If the player stays inside the ring that Williwaw and his clones make, they will take damage due to Williwaw and his clones realigning.

Trivia

 * Williwaw appears to be the icicle inside the cloud and not the cloud itself, due to the cloud being formed out of snowflakes at the start of the fight and the icicle swapping between clouds at the end of the fight.
 * Williwaw is very similar to the planned Cloud Mega elite boss in a few ways, such as being a fourth snowflake form and being a very snowy cloud. Some attacks are also reminiscent of the attacks shown in the drawing of Cloud Mega.
 * Williwaw is the only boss added in the Neapolitan update to not have a champion.
 * Additionally, Williwaw is the only boss found at the end of a floor that doesn't have a champion.