Well, there are many tough enemies, but theese are strongest: Marx, Marx Soul, Galactic Knight, 02, Masked Dedede, Daroach, Dark Daroach, Mecha Kracko, Meta Knigt, Miracle Matter, Fatty Whale, Dark Matter, Dark Mind, Heavy Lobster, Dyna Blade, and Captain Stich. The EASIEST: Bandana Waddle Dee, Ax Knight, Lance Knight, You know, any other swallowable Bosses.
you have to defeat then swallow the cook boss
After you beat a boss in almost any Kirby game he jumps around and spins a bit.
Nightmare is the last boss in Kirby's Adventure for the NES and Kirby: Nighmare in Dreamland for the GBA. He does not, however, appear in Kirby Super Star Ultra.
You can't. After you beat the game, you unlock a boss rush mode.
ender dragon
You have to beat the last boss to get it
The star is the final boss.
bandos
Grab the things made out of yarn that move and then throw them at the boss.
Unfortunately, he cannot. Kirby can, however get something called Triple Star after the final boss.
*Major Spoilers* it is Magalor
Every stage in Kirby 64: The Crystal Shards has 3 Crystals in it (your clearly going to have to do a bit of searching to find most of them). Boss stages give you 1 for successfully beating the boss.