Anniversary Events
Nearly ever year since coming out of Alpha, the TAKP devs have added in some custom content that is available towards the end (sometimes beginning of the next year, depends where it lands) of each year for that specific reset (2 weeks). These events are then removed and won't be available again until the following year. All of the events are available for those two weeks. If any more are added in the future, this will be updated. These are the ones we know of so far.
1st Year Anniversary Event
The Servitor of Gala's coins
Talk to the Servitor of Gala between the soulbinder and the Nexus stone in PoK, and he'll ask you to retrieve his coins. They're scattered all over Norrath -- on Phinny, in the Planes of Fear/Hate/Sky, on solb/lguk nameds, and so on (check the AllaClone list I linked). Turn in a Coin of Gala and you'll get a reward -- including, perhaps, this big ol' bag. (like a Tinkering bag)
Coin of Gala on Allaclone with NPC's it drops from.
Reference: TAKP forums
2nd Year Anniversary Event
Weapon turnins for tokens quest
Talk to this halfling near the PoK main bank. Turn in a weapon and you'll get some number of Action Tokens in denominations A, B or C. Turn in the tokens to Sheriff Roglio in the PoK dark bank for a random quest reward (potions, items, or perhaps a custom title?). Class C tokens are what you need for a chance at the DE illusion clicky mask.
The weapon list from previous years is no longer correct, some of these may still work, but many may not. Luclin weapons were added and some older ones were removed. Gubbin doesn't say what he accepts anymore, so its more of a guessing game now. Please update this when you find something that no longer works or something to add:
Coral Trident - Barnacle Bones in Dagnor Polished Granite Tomahawk - Grenix Mucktail in East Karana or Highpass Hold Langseax or Langseax of the Wolves - Langseax quest in Halas Runed Oak Bow - Coloth Meadowgreen or Kroldir Thunderhoof in South Karana Bone Bladed Claymore - a shadowknight in Befallen Cold Iron Morning Star - a goblin preacher in Permafrost Mystical Claws of Jojo - Jo Jo in Kerra Isle Glowing Iron Pike - Garton Viswin in Mistmoore Polished Steel Dirk - a spectre in the Qeynos Aqueducts Fighting Baton - lumpy goo in the Crypt of Dalnir Fleshripper - Solusek kobold king in Nagafen's Lair Kicsh Der Pavz - Tesch Val Deval'Nmak in Splitpaw Lamentation Blade - Estrella of gloomwater in Kedge Keep Slime Crystal Staff - King Xorbb in his Gorge Axe of the Slayers - Grazhak the Berzerker in Rathe MountainsRuned Falchion - a froglok crusader in lgukBlackened Alloy Longsword - various pickclaw in Runnyeye Blood Fork - spectral knight/protector in Karnor's Castle Messenger of the Queen - Queen Dracnia in Crystal Caverns Spirit Reaver - Jelquar the Soulslayer in Stonebrunt Mountains Pugius - tormented dead and lesser blade fiend in Unrest Bargyn's Torch - Bargynn in Kurn's Tower Glowing Wooden Crook - Lockjaw in Oasis of Marr Axe of the Iron Back - mountain/forest giants in Frontier Mountains, Burning Woods, Dreadlands Bow of the Underfoot - rock golems in the Hole
Reference: TAKP forums
3rd Year Anniversary Event
Memorandums
There is a Dwarf near the GD in PoK that accepts these memorandums and in return you get a chance at some reward. There are a number of different potions you can get from this, such as port and ds pots. The main prize you want from this though is the Seal of the Dwarven Emissary that ports you to Thurgadin. Its unlimited charges and great for most non-porting classes.
Memorandum of Dwarf Slaying on Allaclone is what you hand in to the Dwarf for a chance at this. Some have said they received it after 10 or less turn ins, while others push over 100 without getting one, so RNG be RNG.