Proc Sephuz's Secret Whenever You'd Like in any Situation, Raids included.

Eating the item "Deviate Fish" has the effect of randomly inducing a buff or a debuff. Two of the debuffs, "Sleepy" and "Party Fever" can be dispelled to proc the 70% increased movement speed and 25% Haste for 10 seconds. Remember this can only occur every 30 seconds. Also don't worry about the other buffs you can get. The only "negative" one is the curse, which reduces your stamina, but only by 8 points, which is completely negligible.

Yes this works in raids as well.

Enjoy!