From MHWiki

The M400 is a breed of mouse found when working the final phase of the M400 Hunting Research Assignment. It is known to drop a large variety of loot.

Mouse Group: Zurreal's Breed
Mouse Statistics
Points: 600,000 Gold: 24,400
Location & Attraction Info
Required Power Types: Physical
Other Requirements: None
Cheese: Fusion Fondue Charm: None
Locations: All available to Baron/Baroness
Toxic Spill
Fort Rox
Loot: See below
Larry's Loot Lexicon: MouseHunt Info Page Image: Image Link
The apex of modern mouseology and mousegineering. Combining years' worth of mouse ethology gathered from the top hunters in Gnawnia, the best and brightest minds out of Digby and the top secret equipment held in Laboratory Room #54 resulted in this: the M400 Prototype.

Designed to adapt and camouflage itself as all known breeds of mice, it lives among them in order to analyze and document different mouse behaviours in the wild. Advanced defences make it uncatchable to stay out of hunters' traps, and equally advanced weaponry defends itself against suspicious adversaries.

The perfect mouse... A little TOO perfect. Once the behavioural modules went live, it became sentient, with the belief that it actually was a unique, wild breed of mouse! It easily broke free and has avoided all attempts at recapture.

This "new" breed is next to impossible to find. Recent sightings show that it seems to have made some improvements on itself and the M400 has been spotted in multiple regions simultaneously. Leading us to believe it has some how figured out how to clone itself... What have we done!?
Mouse ID#: 547

Hunting Strategy

To catch M400, the Hunter must do the following Library Assignments:

The mouse requires Fusion Fondue in a designate location when the Hunter is at Step 10 of the Hunting Research Assignment.
Only Physical and Tactical power types work against this mouse.
EMP400 Charm provides a bonus of 25,000 Power against M400.

Fusion Fondue is automatically disarmed upon catching this mouse.

In addition to the normal message about completing a Library Assignment, catching an M400 also leaves this message in the Hunter's Journal:

Just as it was captured, the M400 mouse fired an emergency EMP blast, disarming my bait and warning other M400 Mice in the area!
I will have to start another research assignment to locate where the M400 are now hiding.


The M400 drops a wide variety of loot from the list below.

  • Bonus Points
  • Gold
  • Satchel of Gold (250 gold), (750 gold), (1,000 gold), (2,000 gold), (5,000 gold), (10,000 gold), (50,000 gold)
  • Orbs
  • Skins

History and Trivia

  • The M400 was intended to be the 400th mouse introduced to the game, but its introduction was delayed.
  • 26 February 2014: M400 was released as part of the expansion to Library Assignment.
  • 16 April 2024: The M1000 mouse was released, whose name is an homage to the M400.