- 4: Ronza departs.
- 2: Christmas Tree mice in the Harbour begin to drop Gingerbread Base Blueprints and Gingerbread House Plans
- 2: Festive Comet melts and the Festive Gift Shoppe closes. But hunters will still be able to claim their reward for the 12 Days 'til Christmas event.
- 2: The Great Winter Hunt '09 ends.
- 23: Larry allows players to exchange the 12 loot items from the 12 Days 'til Christmas event for the Christmas Cracker Trap or 10 SUPER|brie+ each.
- 23: Christmas Tree, Gargoyle, Scrooge, and Toy mice start dropping Twelve Liters of Egg Nog as loot in the Festive Comet.
- 22: MouseHunt featured on Toronto news, check out the video here: http://watch.ctv.ca/news/clip248685#clip248685.
- 22: Swiss, Brie, Mistletoe, Mouse Macaroon, and Sleigh Bell are no longer sold in the Festive Gift Shoppe.
- 22: Reindeer Slippers, Yule Log, Festive Restraining Order, Toy Ronza Ship, and Gold Brick are now for sale in the Festive Gift Shoppe.
- 22: Christmas Tree and Frozen mice start dropping Eleven Coloured Lights as loot in the Festive Comet.
- 19: Elf mice are released again.
- 15: Mouse Macaroon, Itchy Sweater, Petrified Fruitcake, Sleigh Bell, Wreath and Slap Cat are now for sale in the Festive Gift Shoppe.
- 15: Gouda, Christmas Coal and Posing Mouse Action Figure are no longer sold in the Festive Gift Shoppe.
- 14: Christmas Tree and Abominable Snow mice start dropping Three Santa Hats as loot in the Festive Comet.
- 08: The Gifts Tab was introduced.
- 03: Festive Gift Shoppe opens, selling Brie, Swiss, Gouda, Christmas Coal, Greeting Card, Icing Sugar, Mistletoe, Plank of Gingerbread, Posing Mouse Action Figure, Slightly Smaller Gift and Candies.
- 03: The Great Winter Hunt '09 begins.
- 03: Candy Cane, Christmas Tree, Nutcracker, Ornament, Present, Scrooge, and Stocking Mice are released.
- 03: Festive Comet crashes into Gnawnia.
- 03: Ronza departs.
- 28: Hollowhead mice are re-released.
- 21: MouseHunt hits 50,000+ users online.
- 20: Giant Speaker, HitGrab Rockin' Horse, Kraken Chaos, Magma Base, and Rainbow Mohawk Wig of Awesomeness available for sale in Ronza's Traveling Shoppe.
- 19: The Birthday Cake Base, HitGrab Horsey, Polar Base, and PartyBot are given the Limited Edition Shield.
- 29: The Ice Maiden weapon is released.
- 29: Mysterious Boxes can now be opened.
- 27: Crunchy, Gumbo, and Shell crafting formulas expanded to include the option to add Magic Essence, resulting in 20 pieces of the cheese.
- 12: The first Ancient Box Trap is crafted.
- 11: Chitinous, Fetid Swamp, Giant Snail, Jurassic, Magma Carrier, Primal, Sorcerer, Stonework Warrior, and Terror Knight mice are released.
- 10: Elub, Nerg, and Derr Chieftain Mice begin dropping Ancient Frayed, Ripped, and Mangled Blueprint Pieces, respectively.
- 05: Hunter Profile updated to include "Mice Caught" and "Rare Breeds Caught" statistics. The "Mouse Tally" is also reorganized into generic difficulty, from most power to least.
- 28: Glitchpaw mice are released in the wake of some downtime caused by overloaded catch statistics, and start to drop SUPER|brie+ as loot.
- 23: The first Elub Chieftain mouse is caught.
- 22: The first Aged, Champion, Defender, Derr Chieftain, Elder, Gladiator, Grandfather, Guardian, Nerg Chieftain, Protector and Slayer mice are caught.
- 21: Alchemist, Alnilam, Alnitak, Beast Tamer, Caretaker, Conjurer, Conqueror, Finder, Grunt, Healer, Mintaka, Mystic, Narrator, Pack, Pathfinder, Renegade, Scout, Seer, Soothsayer, Spellbinder, Taleweaver, Trailblazer, Vanquisher, and Wordsmith mice are released.
- 21: Tribal Isles region is released, introducing the locations Cape Clawed, Derr Dunes, Elub Shore, and Nerg Plains.
- 21: "Hunting tips by Larry" are introduced into the game.
- 22: Champion's Chests and Tournament Tokens are now awarded to the Top 3 and Top 100 teams respectively, in each Tournament.
- 04: Briegull, Buccaneer, Captain, Leviathan, Mermaid, Pinchy, Salt Water Snapper, Shelder, Shipwrecked, Siren and Squeaken mice are released in S.S. Huntington II.
- 19–20: May Giveaway.
- 22: Fairy mice in the Great Gnarled Tree start dropping the Map of the Lagoon, giving access to the Lagoon.
- 20: MouseHunt hits 40,000+ users online at 5:30PM (GMT).
- 09: Gnarled Cheese Curd Potions introduced as loot drops by Bear and Frog mice in the Great Gnarled Tree.
- 09: Centaur, Fairy, Nomad, Tiger, and Wicked Witch of Whisker Woods mice are released in the Great Gnarled Tree.
- 09: The Venus Mouse Trap weapon is released.
- 09: Cyclops mice in the Calm Clearing start dropping the Gnarled Tree Map Piece, giving access to the Great Gnarled Tree.
- 01: Glitchpaw mice are released.
- 31: Bear, Chameleon, Cyclops, Eagle Owl, Elven Princess, Foxy, Frog, Moosker, Shaman, Sylvan, Treant, and Wiggler mice are released.
- 31: Granite mice in the Harbour start dropping the Whisker Woods Clearing Map Piece, giving access to the Calm Clearing.
- 09–13: Ronza's Traveling Shoppe appears, selling Swiss cheese, Splintered Wood, Party Hats, the Birthday Cake Base, the Polar Base, and the HitGrab Horsey.
- 07–09: MouseHunt's Birthday Giveaway.
- 07: Birthday Gifts and Fancy Birthday Gifts can now be unwrapped, introducing Party Hats, the Birthday Cake Base, and the HitGrab Horsey.
- 19: The Arcane Capturing Rod Of Never Yielding Mystery weapon is released.
- 16: MouseHunt hits 30,000+ users online at 4:30 PM (GMT).
- 14–16: Valentine's Giveaway.
- 10: Cupid mice are released.
- 10: The Obelisk of Incineration weapon is released.
- 10: The Hunter's Hammer becomes available for use.
- 04: The first Tattered Mousoleum Map pieces are repaired by the Cartographer, revealing the new Catacombs location.
- 03: MouseHunt hits 100,000 daily active users.
- 03: The Obelisk of Slumber weapon first appears in the Trapsmith tab. It is revealed a day later at the new Catacombs Trapsmith.
- 14: Nibbler mice are released.
- 07: Torn Pages of Plankrun's Journal first released as loot.
- 05: Ronza's Traveling Shoppe departs.
- 01: New Year's Giveaway ends.
- 31: New Year's Giveaway.
- 31: MouseHunt hits 20,000+ users online at 6:00 PM (GMT).
- 25: Gifts and Magically Wrapped Gifts can now be unwrapped, introducing Coal, Hunting Research, and the limited edition Polar Base.
- 15–19: Ronza's Traveling Shoppe appears, selling Swiss cheese, Splintered Wood, and the limited edition Snow Barrage weapon.
- 11: Abominable Snow and Elf mice are released; both drop the regular Gift, with the Elf mice also dropping Magically Wrapped Gifts.
- 04: The Dehydration Base is released with the introduction of Dehydration Base Blueprints for sale at the Harbour General Store.
- 02: Assassin and Hapless mice start dropping Ambush Trap Blueprints. Droid Parts and Rice Paper are released for sale in the General Stores.
- 02: Travel costs are overhauled and are now relative to a player's current location.
- 27: The Token of the Cheese Belt, Token of the Cheese Claw, and Token of the Cheese Fang are found to be dropped by Student mice.
- 27: The first Shredded Furoma Map Pieces are repaired by the Cartographer, revealing the new Dojo, Meditation Room, and Pinnacle Chamber locations.
- 26: Hapless, Master of the Cheese Belt, Master of the Cheese Claw, Master of the Cheese Fang, Master of the Dojo, Student of the Cheese Belt, Student of the Cheese Claw, and Student of the Cheese Fang mice are released.
- 26: Crafting is launched and Combat, Glutter, Rumble, Susheese, and White Cheddar cheese are announced.
- 26: Burroughs Salmon, Cheesy Fluffs, Curds and Whey, Invisi-glu, Ionized Salt, Nori, Paint-brand Paint, Salt, and Splintered Wood are released for sale in the General Stores.
- 26: The Bazaar opens in the Burroughs region. It contains two new shops, the Cartographer and the General Store.
- 20: Assassin mice are released.
- 30–31: Haunted Giveaway.
- 27: Hollowhead mice are first released.
- 10: Lycan mice drop the Shredded Furoma Map Piece, giving access to the Training Grounds in the new Furoma region.
- 06: MouseHunt v2.0 officially launches after several weeks of closed beta.
- 10: The first and only Master Burglar Mouse is caught.
- 09: $2500 Tuesday Event.
- 30: Greater Radioactive Blue Cheese Curd Potions introduced as loot drops.
- 16–18: Hunter's Reward Weekend.
- 15–19: Ronza's Traveling Shoppe makes its first appearance, offering the DeathBot (Chrome Edition) weapon for sale.
- 07: Black Widow mice are released.
- 28: The NVMRC Forcefield Trap weapon is released in both the Town of Gnawnia and Town of Digby Trapsmiths.
- 14: The Marketplace opens.
- 10: Ghost mice are released.
- 10: The Ambrosial Portal, Digby Drillbot, and Sinister Portal weapons are released in the Town of Digby Trapsmith.
- 17: Radioactive Blue Cheese Curd Potions first introduced as loot drops from some of the mice in the Laboratory.
- 12: Monster mice are released.
- 23: Burglar mice are released.
- 01: Mobster mice are released.
- 01: iTunes mice are permanently retired.
- 20: iTunes mice are released.
- 13: Leprechaun mice are released.
- 07: MouseHunt is launched.