I did this glitch in my SM64DS game by accident. You need Yoshi and access to tall, tall mountain and the red switch activated. Pick the second star(I will explain later). Get to Ukiki the monkey. Have him follow you near the river. Flutter jump above the river and try to get him in your mouth as you flutter jump. If done correctly, Ukiki will be in your mouth as you make your way down the river and back to the start point. Now, here's where the Owl comes in. Spit Ukiki out when you hit land, go to the tree(Ukiki will follow you if he's not wearing a cap, so don't hesitate to do this), climb it and let the Owl out. Now for the hardest step in the glitch: Try to get Ukiki in Yoshi's mouth and grab on to the Owl AT THE SAME TIME!!! If you put Ukiki in Yoshi's mouth then try to grab the Owl, Yoshi will spit him out. If done correctly, Yoshi's mouth will be full(sometimes it will, I've done this three times and once Ukiki was in Yoshi's mouth, but his cheeks weren't puffed up)and you will grab a ride on Owl. Go to where the second monkey is(the one that unlocks the cage) stand under the ? box and spit Ukiki out. This next step I've never failed at, but in logical terms it may be difficult to do. Hit the ? box, jump(not flutter jump)slightly(as in just tap the jump button), grab ukiki while in the air, and grab the power flower. If done correctly, Yoshi automatically swallows Ukiki the monkey to grab the power flower. To check and see if you did it right, go to where Ukiki normally is and see if he respawned there. If not, HE'S IN YOSHI'S STOMACH!!! XD Anyway, you can't spit him out, so the only way to fix the glitch is to exit the level. Try it yourself!!!

Yoshisuperstar,out.

Woah...that sounds weird...pretty detailed post.

pieman9 : yeah sorry about that; this is a glitch that has never before been seen until now so i needed to be very specific.

Doesnt sound that insane...just saying

that is a very, very, very interesting glitch
I will have to try it some day...

Woah....so finally we know that Yoshi's a vicious monkey eater XD

I'd try that glitch, but I have a disease called "icantunderstandsuperlongsentencessosorryppliwonttryitattalllolseeyoulater syndrome".

I'm trying it now I'll let y'all know if it works for me

ok, I tried this 5 times....UHG! it's harder than it sounds

but, I'll keep trying.

Speedic : it actually is real hard; The process for me to do it took about 30 minutes.

tried it took 2 trys then it worked
werid never thought yoshi like monkey meat

Finally, got it to work that is very weird

Ha Ha! I Tried It And It Works! It Made Me Laugh So Much! You Should Post That On A Cheat Website To Let Other People Know.

That's a pretty detailed glitch I might go and try it. Even thought it's going to take me a lot of attempts.