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"I've already been infected... Shall we fight for old time's sake?"
―Duff McWhalen, Mega Man X5

Duff McWhalen, known as Tidal Makkoeen[2] (タイダル・マッコイーン Taidaru Makkoīn?) in Japan, is a whale-based Reploid from Mega Man X5.


He was chief of an oceanographic museum and held rank as the captain of a maritime security force. His sometimes reckless behavior often earned him arguments with the Repliforce's navy. Duff guards the ocean (mainly the North Atlantic), which is needed to produce the Hydrogen necessary for the Enigma laser cannon. He was already infected by the Sigma Virus when the Maverick Hunters arrived, and as a final request asks for a fight to the death.


He stays on the right side of the screen and shoots out blocks of ice. The C-Shot and C-Sword will cut through these and also damage McWhalen, as they are his weaknesses. When enough of his energy is depleted, he will swim to the left side and fire ice blocks in rapid succession, trying to push X/Zero into the spiked wall on the right side.

Powers and Abilities

  • Ice Block


Stage Enemies


When playing as X

Duff McWhalen: Oh... Welcome, Captain X.

X: I'd like you to let us use this ocean since it's nearest to the Hunter Base. We need to produce large amounts of hydrogen.

Duff McWhalen: Do you intend it for nuclear fusion? So, then you are going to use the good-old Enigma.

X: Y...yes... If you know that, then please cooperate with us.

Duff McWhalen: X, I'm a man of the sea... ... And I will not allow you to use my sea freely... You might think I'm stupid, but you'll have to fight me!

X: I understand. I accept your challenge!!

Duff McWhalen: The sea is... The sea is already dead... X... I'm a man of the sea... I want to share the same destiny as the ocean... I've already been infected by the virus, too... Do a favor for me... Fight me and let me rest in the ocean... peace...

When playing as Zero

Duff McWhalen: Zero... Long time no see...

Zero: I'm here to secure the ocean nearest the Hunter Base. It has run high...

Duff McWhalen: The Enigma requires a large amount of hydrogen... so you must want the ocean in order to produce hydrogen...

Zero: Precisely. Please cooperate.

Duff McWhalen: I've already been infected... Shall we fight for old time's sake? A duel! And I'll show no mercy!

Zero: Your ship is about to set sail... ...for the last time!

Duff McWhalen: Zero... It's been a long time... But you are later than I expected. Tell me what's been happening on land.

Zero: ............

Duff McWhalen: The world is facing extinction, right? Since I've also been infected with the Virus, why don't you fight me once before you die? A battle between two men! ...Expect no mercy!

Zero: Fine... May you rest in peace... the sea.

Other Media


Duff McWhalen appears in the Rockman X5 manhua, where he battled fellow aquatic Reploid and Maverick Squid Adler.

Archie Comics

Duff McWhalen would later be featured in the Mega Man series from Archie Comics during the Worlds Unite crossover with the Sonic the Hedgehog comics. He is one of a handful of Mavericks to appear on a variant cover, where he is shown being shot at by E-123 Omega of the Sonic the Hedgehog series However, in this version he goes by his Japanese name Tidal Makkoeen, and is a duplicate of the original created by Sigma using the Genesis Portals and Unity Engines.





Production Notes

Developer Comments
This is a boss that got vetoed for X4. He got nixed because it was difficult to personify a whale. If he wasn't humaniform to some extent, he wouldn't look boss-like. I actually wanted to make him about as big as Kibatodos, but he ended up rather compact.[3][4]

Designer Comments
No matter how you tinker with a whale, it still looks like a whale, so I finished this one up comparatively easily. It's a bit of a shock, though, that even though he's a whale, he's smaller than a walrus (Kibatodos). While this guy was being developed, he got impossibly strong when his power dropped, making me feel like crying.[3][4]


  • Duff McWhalen's stage music is a remastered version of Bubble Crab's from Mega Man X2; however, Duff had an original theme before it was scrapped.
  • In the American version, Duff McWhalen was named after Duff McKagan, the former bassist of the rock band Guns N' Roses.[5]
  • He is the only boss in Mega Man X5 whose mugshot is not facing straight forward.
  • He was mentioned in a Nintendo Power article, as the editor said that his name is "one of the worst Mega Man boss names ever".
  • In the Worlds Unite crossover, writer Ian Flynn had intended to use the alternate English name "Tidal Whale" for Duff McWhalen, but the change wasn't made in time and he was featured as Tidal Makkoeen instead.[6]


  1. Mega Man X Official Complete Works, UDON Entertainment Corp. 2009. pg.51. Retrieved on March 30, 2012.
  2. Listed as "Tidal Whale" in Mega Man X Official Complete Works.
  3. 3.0 3.1 Rockman Elysium: Production notes about the cast of X5
  4. 4.0 4.1 Capcom Community: X5 Developer/Designer Note translations
  5. Protodude's Rockman Corner: Alyson Court Talks Mega Man X5 Guns N' Roses References