its a lakitu with a gray cloud that shoots lightning
kill the boss
Monty Tank
You have to have (or be in) mini Mario form and kill the boss in world 5.
if you mean ds,beat world 2's boss as super mini mario.
The boss is bowser.
Defeat Petey Piranha (W5 Boss) as Mini Mario.
go to the 5th world and beat the boss as mini Mario
beat the boss with mega mushroom
beat the last boss in the last castle in world 2 as mini Mario
It is simple. Just beat the world 2 boss as mini Mario. It is the same thing for world 7, but to get to world 7 beat the world 5 boss as mini mario/luigi
this is if you mean new super Mario bros you get a mini mushroom and do the boss with the mini mushroom in world 2 and 5
as tiny Mario defeat world 2 boss than you will go to world 4 problem solved <=)