Ancient Sirehound

The Ancient Sirehound is the final boss of. It is a giant space dog very similar to Oatchi and Moss, speculated by Yonny and Olimar to be the ancestor of all space dogs. They theorize that its descendents evolved to become smaller and were somehow dispersed across the universe, eventually becoming modern space dogs.

While it is said to be rather gentle in most cases, Louie somehow drives it into a rampage, complicating the Rescue Corps' attempts to get the cell sample they need to reverse Oatchi's leaf tail.

The Ancient Sirehound is found on the 20th floor of the Cavern for a King.

When defeated, the Ancient Sirehound drops the Gift of Friendship, but instead of dying, he just loses consciousness and wakes up calmly and runs away.

Strategy
Unlike most previous bosses, the Ancient Sirehound has multiple phases, each with their own health wheel that must be depleted. Its attack patterns will change with each phase.

As it has access to multiple elements, the Candypop Buds on the previous floor may seem useful in order to combat them. However, each Candypop Bud only yields 5 Pikmin, and there is only one of each type, meaning you can only receive 5 of any one Pikmin type. In addition, two of the buds, blue and white, are elemental hazards not present in the fight, and all the others can be avoided or even destroyed by Oatchi.

The superior combat strength of Purple Pikmin is also valuable if the player has access to them, and with 100 Purple Pikmin, and use of ultra-spicy spray it is possible to beat all 4 phases in just 3 attack swarms. If the player has Glow Seeds in their inventory they should consider the use of Glow Pikmin, which are resistant to most of the Sirehound's elemental attacks and can stun it with a glowmob.

Although the Ancient Sirehound has strict damage gates, normally not being able to get less than 3 damage cycles per phase, there is an easy way to defeat it in as little as a single cycle. This requires utilizing Lightning Shock, and having a large number of Purple Pikmin. Use an ultra-spicy spray as it's about to become vulnerable, and once the Ancient Sirehound is down, utilize Oatchi's rush to latch all Pikmin onto it. Then, immediately pull out your Lightning Shock in order to stun it. This will allow you to deal massive damage without it getting up and resuming its attacks. In the case where the amount of Purple Pikmin is less than sufficient (at least 60 or less), it is still easily defeated in 2 cycles instead of the usual 3.

The Ancient Sirehound has a specific yet crucial weakness that can be exploited with the right timing and method. If it charges at Pikmin in an attempt to eat them, and only if it catches at least one Pikmin, it will briefly stop at the end of its charge to devour them. In this window, its tail becomes vulnerable and open to being pulled down. In every phase other than phase 1, the only time the Ancient Sirehound will charge at Pikmin to devour them is if Pikmin are currently affected by a hazard and are panicking. In this instance, it will pause its attacks to prepare a charge. If no Pikmin are caught in its mouth, then its tail will not be vulnerable, so it is crucial to let them get snatched. If done correctly, you can skip most of its attacks with ease.

First phase
In this phase, the Ancient Sirehound mainly attacks with a jumping slam and a charge; the former crushes Pikmin and causes stalactites to drop from the ceiling, and the latter allows it to eat Pikmin that it catches in the charge. It can also swipe at Pikmin if they're too close to it.

To fight it, the player must trick it into charging at one of the fallen stalactites, which will stun it. The player must then have at least 15 Pikmin or two Purple Pikmin grab onto its tail to flip it over and expose its belly to attack. This is the basis for dealing damage in all of the phases. As the Sirehound's health decreases, it will perform more jumping slams before charging.

Second phase
The Sirehound will now begin to use a spread of five snowballs that bounce off of the walls (akin to those of an Arctic Cannon Larva) and a long-range ice breath attack; if it freezes Pikmin, it will follow up with a charge before eating the frozen Pikmin. While it will try to face the player when using the latter, it cannot turn very quickly and its tail can be pulled on as before. However, care should be taken in order to avoid being hit by stray snowballs. The Sirehound will use six, then seven, snowballs as its health decreases, and its ice breath rotation speed increases slightly.

Starting from this phase, touching any part of the Sirehound's body other than its tail will afflict Pikmin with its current element.

Third phase
The Sirehound fights with electrical attacks in this phase. It starts the phase by spitting up three electrical furballs that generate a spread of lightning in a spinning plus shape until they are destroyed, performs an electrical dash attack, and then returns to the center of the arena and produces a set of electric fields around itself. The Sirehound cannot move while using the electric fields, providing an opportunity to attack its tail.

Starting in this phase, the Sirehound will begin to elevate its tail out of reach when not using its "center of the arena" attack. The number of electrical furballs it spits out and dashes it performs before using its electric field attack increases as it takes more damage.

Fourth phase
Changing its element again to fire, the Sirehound will begin to spit fireballs, stomp the ground to produce flaming shockwaves (which Oatchi can jump over), and spit up burning hairballs which produce further shockwaves if they are not destroyed before being hit by a shockwave. The shockwaves cannot hit anything behind the Sirehound and it cannot turn around while performing them, which can be used to get behind it and pull on its tail.

Final phase
Instead of using an element, the Sirehound starts to fly. It will lob projectiles that produce the same gloom that the Smoky Progg uses in a circular area when they land, and will also use a beam of this gloom to attack in a line. Despite the previous phases using hazards, and the poisonous appearance of the boss during the phase, the gloom will kill every Pikmin type.

The player must navigate between the gloom patches, ideally by riding on Oatchi, without being hit by the beam to get underneath the Sirehound and pull on its tail once more. At low health, it will begin to panic Pikmin with its close-range roar and may quickly reposition itself to keep its distance from the player. This roar is to be treated with maximum and utmost caution, as this will cause dozens of your Pikmin to run directly into the many puddles of gloom, insta-killing them in the process.

Despite this phase having the highest potential for danger and mass destruction of your squad, it also has the easiest weakness of all the phases. If one simply activates a Lightning Shock item while it's in the air, or utilizes a Glow Mob to stun it, the Ancient Sirehound's tail will fall down and immediately become vulnerable, allowing for a quick and harmless knockdown. If the player has enough Lightning Shocks, then it's possible for not a single attack to be performed by it.

Upon losing its last health wheel, the Ancient Sirehound will be defeated and run away, leaving behind its collar and Louie. If one defeats it in the Piklopedia, it will simply fall asleep, now docile.

Locations

 * Cavern for a King: The Sirehound appears at the very last sublevel of the cave, in its 20th sublevel. It appears with both Louie and the Gift of Friendship in tow as what is usually the last possible collectibles in the main campaign.

Trivia

 * The Ancient Sirehound bears a great resemblance to a real-life breed of tiny dog called a . When compared to real-life sizing, the Sirehound would be about the size of a Shih Tzu puppy. It also may be based on a.
 * The Ancient Sirehound is one of the two enemies in the Pikmin series to have sequential health meters, the other being the Waterwraith. It also has 9,000 HP for each meter, meaning the Ancient Sirehound has the highest HP of any enemy in the entire Pikmin series, with a total of 45,000 health.
 * Self-resurrecting enemies, such as the Spotty Bulbear and the Gatling Groink, can fill their meter from empty to full, however this is technically the same meter and not a new sequential meter.
 * Technically, the Titan Dweevil has sequential healthbars, but those only apply to the weapons that are required to be knocked off before the boss itself can be damaged.
 * When being fought in the Piklopedia, it is possible for it to jump on top of the walls of the arena.
 * After the Rescue Corps cure Oatchi and leave PNF-404, the Ancient Sirehound is seen docilely following Moss and the Pikmin. One randomly determined straggler Pikmin will get spooked by the Ancient Sirehound and run off.