Tattoos are status symbols with the Kingdom of Loathing. You receive your first simply by selecting your class. They are displayed on your character sheet, for all to see.

They are acquired by visiting the Pretentious Artist. You must complete his quest before he will paint any tattoos for you.

Tattoos are managed in the Account section. Selecting a tattoo will display it on your character sheet.

There is even more about this in the KoL Wiki, which can be viewed here.

Class
	Accordion Acquired: Starting tattoo for Accordion Thieves, or ascending to an Accordion Thief.
	Shining accordion Acquired: Ascending as a hardcore Accordion Thief.
	Triple-Shining accordion Acquired: Ascending as a hardcore Oxygenarian Accordion Thief.
	Club Acquired: Starting tattoo for Seal Clubbers, or ascending to a Seal Clubber.
	Shining club Acquired: Ascending as a hardcore Seal Clubber.
	Triple-Shining club Acquired: Ascending as a hardcore Oxygenarian Seal Clubber.
	Disco Ball Acquired: Starting tattoo for Disco Bandits, or ascending to a Disco Bandit.
	Shining disco ball Acquired: Ascending as a hardcore Disco Bandit.
	Triple-Shining disco ball Acquired: Ascending as a hardcore Oxygenarian Disco Bandit.
	Pasta spoon Acquired: Starting tattoo for Pastamancers, or ascending to a Pastamancer.
	Shining pasta spoon Acquired: Ascending as a hardcore Pastamancer.
	Triple-Shining pasta spoon Acquired: Ascending as a hardcore Oxygenarian Pastamancer.
	Saucepan Acquired: Starting tattoo for Saucerors, or ascending to a Sauceror.
	Shining saucepan Acquired: Ascending as a hardcore Sauceror.
	Triple-Shining saucepan Acquired: Ascending as a hardcore Oxygenarian Sauceror.
	Turtle Acquired: Starting tattoo for Turtle Tamers, or ascending to a Turtle Tamer.
	Shining turtle Acquired: Ascending as a hardcore Turtle Tamer.
	Triple-Shining turtle Acquired: Ascending as a hardcore Oxygenarian Turtle Tamer.
Custom
	Bunny Acquired: Unique tattoo given to ZetaReticula (#80507) for getting real life tattoos of KoL artwork.
	Cutter Acquired: Unique tattoo given to Daisy Cutter (#13041) for having a real life KoL tattoo.
	Daisy Acquired: Unique tattoo given to corneliusv (#549464) for having a real life KoL tattoo.
Miscellaneous
	Martini Acquired: There's a slight chance of getting it every time you drink a martini.
	Paint Palette Acquired: Complete the Pretentious Artist quest.
Outfits
	Armor Acquired: Visit the Pretentious Artist while wearing the Antique Arms And Armor outfit.
	Axe Acquired: Visit the Pretentious Artist while wearing the Knob Goblin Elite Guard Uniform outfit.
	Beer can Acquired: Visit the Pretentious Artist while wearing the Frat Boy Ensemble outfit.
	Bugbear Acquired: Visit the Pretentious Artist while wearing the Bugbear Costume outfit.
	Crimbo Light Acquired: Visit the Pretentious Artist while wearing the Bow Tux outfit.
	Crimbo Wreath Acquired: Visit the Pretentious Artist while wearing the Arboreal Rainment outfit.
	Elbereth Acquired: Visit the Pretentious Artist while wearing the Yendorian Finery outfit.
	Gift Acquired: Visit the Pretentious Artist while wearing the Crimbo Duds outfit.
	Knob Heart Acquired: Visit the Pretentious Artist while wearing the Knob Goblin Harem Girl Disguise outfit.
	Loser Acquired: Visit the Pretentious Artist while wearing the Furry Suit outfit.
	Ninja Acquired: Visit the Pretentious Artist while wearing the Hot And Cold Running Ninja Suit outfit.
	Peace symbol Acquired: Visit the Pretentious Artist while wearing the Filthy Hippy Disguise outfit.
	Pickaxe & Shovel Acquired: Visit the Pretentious Artist while wearing the Mining Gear outfit.
	Radio Acquired: Visit the Pretentious Artist while wearing the Radio Free Regalia outfit.
	Skull & Crossbones Acquired: Visit the Pretentious Artist while wearing the Swashbuckling Getup outfit.
	Snowflake Acquired: Visit the Pretentious Artist while wearing the eXtreme Cold-Weather Gear outfit.
	Star Acquired: Visit the Pretentious Artist while wearing the Star Garb outfit.
	Sword Acquired: Visit the Pretentious Artist while wearing the 8-Bit Finery outfit.
	Canadia Acquired: Visit the Pretentious Artist while wearing the OK Lumberjack outfit.
	Clockwork Acquired: Visit the Pretentious Artist while wearing the Clockwork Apparatus outfit.
	Gnauga Acquired: Visit the Pretentious Artist while wearing the Gnauga Hides outfit.
	Cloaca-Cola Acquired: Visit the Pretentious Artist while wearing the Cloaca-Cola Uniform outfit.
	Dyspepsi Acquired: Visit the Pretentious Artist while wearing the Dyspepsi Uniform outfit.
	Hourglass Acquired: Visit the Pretentious Artist while wearing the Time Trappings outfit.
	Egg Acquired: Visit the Pretentious Artist while wearing the Grass Guise outfit.
	Jellyfish Acquired: Visit the Pretentious Artist while wearing the Encephalic Ensemble outfit.
	Recyclables Acquired: Visit the Pretentious Artist while wearing the Glad Bags Glad Rags outfit.
	42 Acquired: Visit the Pretentious Artist while wearing the Terrycloth Tackle outfit.
	Clown Acquired: Visit the Pretentious Artist while wearing the Terrifying Clown Suit outfit.
	Pineapple! Acquired: Visit the Pretentious Artist while wearing the Tropical Crimbo Duds outfit.
	Black Armor Acquired: Visit the Pretentious Artist while wearing the Black Armaments outfit.
	Palm Acquired: Visit the Pretentious Artist while wearing the Palmist Paraphernalia outfit.
	Frat Warrior Acquired: Visit the Pretentious Artist while wearing the Frat Warrior Fatigues.
	WAR Acquired: Visit the Pretentious Artist while wearing the War Hippy Fatigues.
Ascension Tattoos
	One Acquired: Ascending softcore for the first time.
	Two Acquired: Ascending softcore for the second time.
	Three Acquired: Ascending softcore for the third time.
	Four Acquired: Ascending softcore for the fourth time.
	Five Acquired: Ascending softcore for the fifth time.
	Six Acquired: Ascending softcore for the sixth time.
	Seven Acquired: Ascending softcore for the seventh time.
	Eight Acquired: Ascending softcore for the eighth time.
	Nine Acquired: Ascending softcore for the ninth time.
	Ten Acquired: Ascending softcore for the tenth time.
	Eleven Acquired: Ascending softcore for the eleventh time.
	More than eleven Acquired: Ascending softcore for the twelfth time.
	One Acquired: Ascending hardcore for the first time.
	Two Acquired: Ascending hardcore for the second time.
	Three Acquired: Ascending hardcore for the third time.
	Four Acquired: Ascending hardcore for the fourth time.
	Five Acquired: Ascending hardcore for the fifth time.
	Six Acquired: Ascending hardcore for the sixth time.
	Seven Acquired: Ascending hardcore for the seventh time.
	Eight Acquired: Ascending hardcore for the eighth time.
	Nine Acquired: Ascending hardcore for the ninth time.
	Ten Acquired: Ascending hardcore for the tenth time.
	Eleven Acquired: Ascending hardcore for the eleventh time.
	More than eleven Acquired: Ascending hardcore for the twelfth time.
	No eating Acquired: Ascending as a hardcore Boozetafarian.
	No drinking Acquired: Ascending as a hardcore Teetotaller.
	All I Need Is The Air That I Breathe Acquired: Ascending as a hardcore Oxygenarian.