See Notes section for tasks that must be completed to obtain and wear.

Purchased from the Museum guard on the top floor of the Varrock Museum

Worn for protection; and can provide the perks for up to three different skill capes (See Notes).

The Completionist cape is the most powerful cape in the game. When purchased, it comes along with a Completionist hood which can be added to it to create a Hooded completionist cape.

The cape has the arrow collecting ability of Ava's Alerter, the Ardougne cloak 4's ability to teleport the player to the East Ardougne monastery and farming patch, as well as the enhanced thieving abilities. It also is acts as a TokHaar-Kal for fighting Ice Strykewyrms. Like the Max cape, the colors of the Completionist cape can be customized by using the menu opened by right-clicking the cape. It will also unlock 'the Completionist' title the first time you wear it.

The tasks for obtaining the Completionist cape include:

Task Name	Description
Abyssal Reach	Unlock access to the Abyss(via Mage of Zamorak miniquest).
Almost as Perky as a Prawn	Obtain all 15 Prawn Perks from your Aquarium.
Annihilator	Earn "the Annihilator" title by fighting all four nihil at once.
Arc I - Flag Fall	Complete Flag Fall.
Arc II - Head of the Family	Complete Head of the Family.
Arc III - Spiritual Enlightenment	Complete Spiritual Enlightenment.
Arc IV - Jed Hunter	Complete Jed Hunter.
Arc V - Eye for an Eye	Complete Eye for an Eye.
Arc VI - Harbinger of Doom	Complete Harbinger of Doom.
Arc VII - Tuai Leit's Own	Complete Tuai Leit's Own.
Arc VIII - Ghosts from the Past	Complete Ghost's from the Past.
Arc IX - Damage Control	Complete Damage Control.
Arc X - Final Destination	Complete Final Destination.
Arc - Ancient Eastern Tortle Portals	Activate all Tortle Portals on The Islands That Once Were Turtles.
Arc - Unlocking Waiko	Purchase the following unlocks from the Waiko Reward shop: 'Waiko Grill' 'Whale's Maw Camp Fire' 'Whale's Maw Deposit Box' Arc journal teletabs Crystal tool siphon blueprints
Arc - Upgrading Waiko	Purchase the following first tier upgrades from the Waiko Reward shop: 'Commodity Sell Per Day Increase' 'Supplies Cap Increase' 'Contracts Per Day Increase' 'Supplies Cost Reduction' 'Commodity Sell Price Increase'
Bandos' Memories	Recover all 14 of Bandos' Memories on Yu'Biusk.
Bane Tuner	Unlock Spell: Tune Bane Ore (Ritual of the Mahjarrat).
Big Chinchompa	Obtain a score of at least 1,111 in round of Big Chinchompa.
Bipedal Mask	Complete a Tuska Mask.
Bridge over Fremmy Waters	Complete the unabridged Fremennik Sagas.
Claus is Rising	Assist Claus the chef and claim his reward after Carnillean Rising.
Deadlier Catch	Hunt the Thalassus ten times after Deadlist Catch.
Desert-ed Ghosts	Uncover the ghostly backstory around Desert Treasure via The Curse Of Zaros.
Diaries of the Clans	Find all journal eight pages on the Hefin Agility Course.
Elven Titles	Earn the Elven clan titles Earn "of the Amlodd" title by speaking with Lord Amlodd while having a Light creatures special ability active. Earn "of the Cadarn" title by besting 1,000 of Cadarn's Elves in combat. Earn "of the Crwys" title by checking the health on an Elder tree. Earn "of the Hefin" title by completing 200 laps of the Hefin Agility Course. Earn "of the Iorwerth" title by completing eight Dark Beast tasks assigned by Morvran. Earn "of the Ithell" title by creating 100 Crystal flasks. Earn "of the Meilyr" title by harvesting 50 Harmony Moss. Earn "of the Trahaearn" title by Mining and Smithing 100 Corrupted ore.
Family Spirit Tree	Reconnect the Prifddinas Spirit tree with her brethren.
Famous	Earn the title 'The Famous' by completing Morvran's Slayer challenge.
Heal, Quickly	Unlock the prayer: Rapid Renewal.
I'm Forever Washing Shadows	Help Lord Amlodd in cleansing 15 of each shadow core.
Imping Around	Catch one of each impling for Daffyd.
Invention Gives Me the Blues	Purchase all blueprints for the Invention Technology tree devices.
Kharshai's Memories	Recover all 15 memories for Kharshai during the Mahjarrat Memories miniquest.
Kiln Fighter	Complete the TokHaar Fight Kiln.
Kudos to You	Earn all Varrock Museum Kudos.
Long Live the Queen	Defeat the Queen Black Dragon and claim the First dragonkin journal.
Lost Toys	Find all thirteen Vampyre plushies in Morytania for Lex.
Lunar Master	Unlock all 11 Lunar spells from Livid Farm.
Make Them Bleed	Perform well enough in Rush of Blood to impress Morvran.
Master Quester	Complete all Quests.
Master Skiller	Level all skills to their maximum level: 120 Dungeoneering, Invention, and Slayer, 99 in all other skills.
Memories of Guthix	Attune and hand all engrams in to the Memorial to Guthix.
Music Maestro	Unlock all pieces of music.
Myreque in Memoriam	Complete the Memorial for the Myreque and help Veliaf move on.
One Foot in the Grave	Attend the funeral of Clarence the mage, and receive your reward (Returning Clarence miniquest).
Out into the Ourania	Unlock the spell: Ourania Teleport.
Peachy Bones	Unlock Spell: Bones to Peaches (Mage Training Arena).
Pious Prayers	Unlock the prayers: Chivalry, Piety, Rigour, Augury.
Port Life	Complete the Player-owned Ports tutorial.
Potion For a Lady	Find Lady Meilyr's lost potion recipes in Dungeoneering.
Potion Mixer Master	Unlock all of the combination potion recipes from Clan Meilyr in Prifddinas.
Reaper Crew	Defeat every boss at least once to earn the title 'the Reaper'.
Rhian in Gold - The Original	Fully build the statue of Rhiannon in the Tower of Voices at least once.
Seren Memories	Deposit Seren memoriam crystals, then search the Sanctum alcove.
Sing For the Lady	Help Lady Ithell with crystal singing research.
Slayer Master	Earn the title 'Slayer Master' by clearing wave 20 on platinum difficulty in Rush of Blood.
Stay Safe	Reach the end of the Stronghold of Player Safety.
Stay Secure	Reach the end of the Stronghold of Security.
Task Master	Complete all Tasks.
Tell Tale Tarn	Find out about Tarn Razorlor's secrets in The Lair of Tarn Razorlor.
Trio to the East	Complete any of the trio story lines in Ports: Hyu-Ji, Quin, Eastern Curiosities, or Guardians of the World.
Troublesome Crystals	Find all of the memoriam crystals in Prifddinas.
Uncorrupted Ore	Aid Lady Trahaearn in removing some corruption by smelting 100 Corrupted ore in the Trahaearn Clan furnace, then claiming a Smithing lamp from her.
Walking the Reef	Find all 4 pieces of the Reefwalker's Cape forgotten scroll.
What's Mine Is Also Doric's	Complete all the Doric and Boric Tasks.
Yaktwee's a Charm	Unlock the Enhanced Yaktwee stick by catching 1,000 Charm sprites.
You Be Dead	Bury all of the goblin priests in Yu'biusk.
Zarosian Memories	Deposit Zarosian memoriam crystals, then search the Sanctum alcove.

After completing an even longer list of requirements that practically amounts to finishing the game, the cape will become a Completionist cape (t).

Along with the Max cape and Completionist cape (t), this cape can be fed any of the normal Skillcapes in order to obtain their perks. Note that you can only have up to 3 perks on the cape at one time (removing a perk will not return the cape) and they are shared amongst the capes. Meaning that if you use the Cooking cape on this cape, both the Max cape and Completionist cape (t) will also obtain the perk, if you have one of them.
The available cape perks include:

Cape	Perk
Agility cape	Gives a chance of double tickets from the Brimhaven Agility Arena. Stacks with the Karamja task set reward.
Attack cape	Gives a chance for degradable items not to degrade.
Constitution cape	Doubles life points regained over time.
Construction cape	Reduces the cost of creating planks.
Cooking cape	Prevents food from being burned.
Crafting cape	Thread is no longer needed when crafting.
Defence cape	Acts as a sign of life. Same cooldown.
Divination cape	Gives a chance of saving Divination materials.
Dungeoneering cape	Teleport to any available resource dungeon.
Farming cape	Gives a chance of instantly harvesting a patch.
Firemaking cape	Active to light a fire on the spot you're standing on.
Fishing cape	Gives a chance to get a double catch.
Fletching cape	Gives a chance of automatically stringing a bow when Fletching unstrung bows.
Herblore cape	Activate to clean all herbs in your inventory for no XP.
Hunter cape	Activate to give your Herblore Habitat vine plant the effects of its hunter potion.
Invention cape	Slows the drain of invention charge.
Magic cape	Activate to swap spellbooks at banks.
Mining cape	Gives an invisible +2 skill bonus.
Prayer cape	Imparts the same benefits as lit burners in a player-owned house.
Ranged cape	Acts as Ava's devices(Ava's accumulator, Ava's alerter, Ava's attractor).
Runecrafting cape	Activate to reveal the required rune for the Rune Goldberg Machine.
Slayer cape	Activate to teleport to any Slayer master in the game that you can access.
Smithing cape	Gives the same effect as the goldsmithing gauntlets.
Strength cape	Dismember lasts an additional 2 seconds.
Summoning cape	Gives a chance to save charms when infusing pouches.
Thieving cape	Lowers your stunned time when caught from 4.2 seconds to 3.
Woodcutting cape	Provides an increased chance at finding bird's nests and crystal geodes.
Quest point cape	Adds 30 seconds onto your Tears of Guthix time.

0.4 kg

A cape worn by those who've over achieved.