How do you beat Elder shroob

You talking about Elder Shrooboid at Star Mtn? (Or whatever it's called. Haven't played the game in years.) I know you don't jump on his head, as the spikes damage you. Use Bros. Items and Hammers. Eventually after doing enough damage he'll get bigger, making his attacks change. This was a hard battle to do, so I suggest you save before the battle incase you die. Good luck.

Once you have made him bigger, you must dodge all of his attacks, and keep hurting him (or her). When he throws the big spike ball at you, hit it with your hammers; have mario hit it and it will fly above you, and luigi hit it to have it go above the shrooboid's head. Keep hitting the spaceship with it to increase your time limit. If it hits zero, over him or you, you immediatly die. Keep doing this until it explodes. He has at least 1700 HP, so buy lots of one up mushrooms, or one up supers to keep you going.

It's easy my friend teached me something to beat all enemies do not skip one so you could have a lot of power when that time comes and by the way when that time comes reccommended item's are ice flower's green shell's(only when hes brought down)and copy flower's are reccommended

Just us mix flower or cheat.

You have to pound him with attacks. I suggest Red Shell's and Mix Flowers. He occasionally will throw a spike ball. It will go in circles around you. Hit it with the hammer fast, and he will fall over and his back will be vulnerable. Use Copy Flowers and keep on attacking. He will then grow big. Continue attacking but keep the timer up high, and you will eventually win. Use lots of Ultra Mushrooms, 1-UP Supers, and Ultra Drops. Good luck!

I observed that Ice Flowers do critical damage to him, so there' so tip. I just barrage him with ice flowers, red shells, mix flowers, and repeated copy flower when he's down.