Prince_Of_Darkness

If you are refering to Titan Dweevil heres how I did it:
1. I took 30 red, 30 blue, 30 yellow and 10 whites in the hole.

2. At the boss leave Shyacho with your yellows, reds and whites.

3. Take your blues and attack the tap on him.
4. If the Titan is turning blue switch to Shyacho and make sure your pikmin don't drown.

5. If he turns Red, Yellow or Pink get your blues as far away as possible.

6. Repeat 4-6. until tap falls off

7. Go back and switch your blues for yellow.

8. Attack the Glass object like you did the tap.

9. I did the Flare Cannon next, with my reds but you don't have to.

10. Attack the Comedy Bomb with your whites until it falls off as well.

11. His armour should fall off and you can attack him with all your Pikmin till he dies.

Good Luck.