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Hydrus is the fan name given to the seventh colossus. Resembling an electric eel and a catfish, this colossus swims in a giant, murky lake at quadrant D1.

Path to the colossus

See also: Map for this path

Shadow of the Colossus - 7th Colossus 1 2

Video - Path to Hydrus

Head north from the shrine across the land bridge. From here, there are two ways of getting to the lake. The most direct path is to proceed as if traveling to Gaius, but to continue on to the Stone Arch Gorge (quadrant D2), then head north to the lake. It is easy to get lost this way, however, as there aren't too many opportunities to get help from the sword's light in the dark canyons. The easier, but slightly longer way is just to go straight north to quadrant F1, then go east through the Dried Marsh (quadrant E1). The entrance to the lake will be in plain view, and the sword can be used anytime. There is a stone path leading out to around the middle of the lake, where there will be a pillar with a spiral walkway wound around it. The player can use this walkway to reach the lake, or they could just dive in. Either way, Agro will have to watch from where she is.



Shadow of the Colossus - 7th Colossus 2 2

Video - Battle with Hydrus

Hydrus will be swimming deep underwater when Wander dives in. There is no special way of luring it up; just swim around above it and eventually it will make a pass at Wander. When it does, the player will have to grab on, but doing so isn't easy. The colossus is protected by three, giant, electric spikes protruding from its back, which activate a sphere of highly-damaging electricity when submerged. The only safe spot is the area of fur at the end of its tail.

Once Wander's been dragged through the water, the colossus will swim around at the surface of the lake, going in and out of the water to try and dislodge Wander with its electrical spikes. The sword will show the player a small place where they can stab at the base of each spike to disable them, but be very careful; this requires a near-fully charged stab at least, and the electricity will deal a massive amount of damage to Wander if he's too slow. One may not have time to disable all three spikes before Hydrus dives back underwater, which will eventually force Wander off. The colossus will soon resurface, however, and Wander doesn't have to disable any spikes he took out previously. When one finally makes their way to its head, they'll find its only major sigil. Hydrus will continuously bob its head up and down in the water, so time stabs thoughtfully, as the colossus cannot be stabbed when submerged.

Time Attack times in Original and PS3 versions (Normal, Hard): 12:00, 8:00
Time Attack times in PS4 Remake (Normal, Hard): 9:00, 7:30


Location Percentage of health
Normal Hard
On its head 100% 100%
Behind each spine (3) Kills electric organs

Tips and tricks

  • It is possible to run past the first two spikes, but the player must be extremely quick. With the small health bar given in Time Attack, the damage incurred from messing up will nearly kill the player. The final spike must be taken out, as it protects the colossus' head.
    • It is possible to roll underwater while riding Hydrus, and this can help with bypassing the electricity (On PS4 it only works with classic controls).
  • There are are a few ways to know that Hydrus has submerged when on him. These are all helpful in time attack, as the player can then just quickly let go and repeat the process of getting on him.
  1. The first and easiest one is the music changing. If Hydrus goes underwater while on him and “Silence” starts playing, that means he won’t come back up.
  2. The second one is the depth. When submerging, Hydrus will go really deep, and most of his will go underwater.
  3. The final one is time, as when parts of Hydrus go underwater when he tries to shake Wander off, it will take a few seconds for them to resurface. If most of his body doesn’t come back up in that time zone, it means he has submerged.


Attack Damage (Normal) Damage (Hard) Description Demonstration
Surface Shock 15 40 When the colossus goes to the surface, its three electric horns will come out, dealing damage each type Wander touches the electricity. Try to avoid swimming directly above it. EelSurfaceShock.gif
Submerged Shock 15 40 The colossus will keep submerging and resurfacing once Wander is on its back. Don't stay close to the horns during the process or you'll receive damage. It's also possible to take damage multiple times. EelSubmergedShock.gif


Phase Plays in Music
Intro Plays after passing under the arch at the beginning of the bridge over the Lakeside. Lakeside

Phase 1 Plays once Wander hits the water and the battle starts. Silence

Phase 2 Plays once Wander grabs onto Hydrus. In Awe of the Power


  • Hydrus is one of only two colossi that are fought in a body of water; the other water-dwelling colossus is Pelagia.
  • Hydrus is the first of three limbless, serpentine colossi the player faces over the course of the game, the other two being Dirge and Phalanx.
  • Hydrus is the second-longest of all the colossi after Phalanx.
  • Hydrus is one of the furthest-situated colossi from the central Shrine of Worship and is also one of the most northerly of all; Argus and Celosia are roughly as far north as Hydrus.
  • Hydrus makes a lot of whale-like noises.
  • After being defeated, Hydrus' body is seen sinking to the depths of the lake in which it resided. However, upon revisiting the lake after Hydrus has fallen, its body will have risen to the surface again. This is so that the player can enter Reminiscence Mode if they wish to do so. This is also true of Avion and Pelagia.
  • Prior to Wander entering the lake and initiating the fight, Hydrus can be easily spotted due to the fact that its three electrical spines discharge electricity even before the fight begins. However, if one observes Hydrus before the fight begins, it remains totally stationary and will only move once Wander enters the lake and Hydrus' introductory scene plays.
  • Hydrus is the last colossus until Cenobia to have an introduction scene that shows the area where the battle takes place.
  • Of all 16 colossi, Hydrus is the only one that Wander is capable of rendering completely harmless; once its three electrical spines have been nullified, Hydrus has no other means of attack and will no longer be able to inflict any damage at all. It will continue to make passes at Wander as though it is still capable of electrocuting him, but since it cannot do this, it merely passes beneath Wander without him taking any damage.
  • While all colossi have all or nearly all of their health in their major sigils, some colossi have minor sigils which count as a very small percentage of the colossus' health. Hydrus is a unique case, however, as the three minor sigils behind each electric organ combined is nearly 35-40% of its total health.
  • While at first Hydrus might seem very docile like Avion or Phalanx, it is in fact hostile, as when it swims up towards Wander, Hydrus' eyes turn orange. However, it always passes just a little bit below Wander, seemingly unable to physically ram him from below.

  • Earlier concepts of Hydrus show Wander being able to hold onto his sword after stabbing it in the colossus' body. This feature is also seen in the pilot movie of "NICO".
  • Also in an early concept, Wander is seen holding onto a harpoon while climbing it, possibly suggesting the weapon was planned to be a normal item.
  • The harpoon is also seen in Pelagia's concepts.
  • Hydrus was the 5th colossus in the E3 Demo version. Its fight was much more frustrating, as the water stopped you from being able to grab onto its fur, making you go back to where you started. Its electric spikes were also different, having an animated circuit-like texture in place of the minor sigils. The major sigil was also placed at the same spot as the final minor sigil, so the player would deal damage and disable the final spike at once. It also had bright green fur.


The Game Shadow of the Colossus ( Demo  · Pal Release  · Shadow of the Colossus HD  · PS4)
Characters Wander  · Agro  · Mono  · Dormin  · Emon
The Colossi I  · II  · III  · IV  · V · VI  · VII  · VIII  · IX  · X  · XI  · XII  · XIII  · XIV  · XV  · XVI
Unused Colossi ( Devil  · Evis  · Griffin  · Phoenix  · Roc  · Saru  · Sirius  · Spider  · Worm  · Yamori A  · Datamined Colossi)
Magic Sigil  · Hard Mode
Colossus Arenas Temple  · Proto  · Arena  · Kirin's Hill  · Canyon · Canossa  · Lakeside  · Underground  · Geyser  · Gravewind  · Leo's Cave  · Poseidon's Lake  · Desert  · Ruins  · Parthenon  · Sanctuary
Unused Arenas ( Badlands  · Cave  · Crater  · Devil's Plain  · Dune  · Hillock  · Labyrinth  · Sluice  · Stonehenge  · Valley )
The Forbidden Lands Shadow creaturesSave shrinesFruit treesWhite-tailed lizards

The Shrine of Worship
Umbral GladeStone Arch GorgeDried MarshNorthern SpanDesert FortressMisty FallsRavine EntranceHalf-moon CanyonWestern PlainRound Stone HillLair to the WestStone Bridge CliffCliff PathLair on the MesaWestern CapeArch Bridge PlainBlasted LandsAutumn ForestEastern BluffValley PlainSouthwestern CapeSouthern PlainGreen CapeThe Broken Seal

Soundtrack Roar of the Earth
Walkthrough Time AttackGolden Coins
Other media Nico  · Official artbook/guidebook  · Collectible figurines  · Film adaptation
Giantology campaign
Hoaxes Jebal-Barez skeletonTamil Nadu tsunami giantSulu Sea eel statuePolarneft conspiracySayre family vacation
Characters Eric BelsonCasper ShillingEd GuylerArkady SimkinBoris AtlasovAndrew and Ellie Sayre
Media Giantology podcasts (FirstInterview with Arkady SimkinThirdFourth) • IPICP memo
SotC Template CoverLogov2.png Walkthrough
Characters Wander  · Mono  · Agro  · Dormin  · Lord Emon  · Guards  · Shadow Creatures
Colossi I  · II  · III  · IV  · V · VI  · VII  · VIII  · IX  · X  · XI  · XII  · XIII  · XIV  · XV  · XVI
Locations The Forbidden Lands  · Shrine of Worship  · Colossus Arenas
Main Items Power-ups (Lizards · Fruit) · Weapons (Ancient Sword · Sword of the Sun · Queen’s Sword · Sword of Dormin · Bow & Arrow · Ancient Bow · Harpoon of Thunder · Life Sword) · Collectibles (Relics)
Gameplay Hard Mode  · Save shrines  · Time Attack  · Reminiscence Mode  · Watermellon  · Barrel
Media Roar of the Earth (OST)  · Official Art and Guide Book  · Nico Bonus DVD  · Film
Releases OPM Demo  · PS2 original  · PS3 remaster  · PS4 remake  · Credits
Early Builds Preview version  · PSU Preview version  · E3 Demo
Unused Content Unused Colossi  · Datamined Colossi  · Colossus Test Stages  · Unused Locations  · Beta Mountains  · Shadow of the Colossus Development Phases