|“||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!||„|
|~ Duff McWhalen|
Duff McWhalen, known as Tidal Makkoeen in Japan and Tidal Whale in Mega Man X Legacy Collection 2, is one of the eight Maverick bosses in Mega Man X5.
Duff McWhalen was the chief of a oceanographic museum and captain of a maritime security force, keeping watch over the northern Atlantic Ocean. During the Earth Crisis, the Maverick Hunters seek out Duff McWhalen, as they needed to secure the ocean near the Hunter's base to produce hydrogen to power up the Enigma cannon. Having already been infected by the Sigma Virus, Duff asks the Hunters to have a final duel with him before allowing them to use the ocean, ending defeated by them.
Duff McWhalen's main form of attack is to create a maze of ice blocks, stopping to shoot his Goo Shaver which slides on the blocks. He will then attract the ice blocks to the spiked wall behind him while shooting small torpedoes at the player. When low on health he will dive to the other side of the arena and fastly shoot ice blocks to push the player into the spike wall. His weaknesses are the C-Shot with X and C-Sword with Zero.
- In the initial English localization of Mega Man X5, Duff McWhalen was named after the Guns N' Roses bassist, Duff McKagan.