Hardest Yoshi level

I don't remember why I picked up Yoshi's Island, but I became hooked on the game. I am almost at 100% on every level, but there are some ones I thought were insane. Any hardest levels for you?

Also I 100% Yoshi's Island DS

I have no frame of reference for the series as a whole, but Skeleton Goonies' Lava Lair is a brutal combination of precision and advance planning. With no stable ground, lava below, and wide gaps between the ground, the only way forward is through careful use of the Flutter Jump to avoid losing height while avoiding flocks of Skeleton Goonies. But you often need to gain height to reach items and avoid hazards, so this means stomping on those same Skeleton Goonies, with the punishment for missing being to lose a bunch of height and potentially collide with the lava. Further, sources of yarn balls are limited, so the player has to find the time and space to eat at least some of the Skeleton Goonies without taking hits and with time left to bounce off the others.

Wonderful World of Wool is also tricky, but less for straight platforming and more that its an endurance match against a fairly long checkpointless course with instant death littered across the back half. Those sections being either literal autoscrollers or practical autoscrollers also means zipping through the danger zone (as one often does in order to get max heart scores after already locating the other collectables) isn't an option.

During my time playing New Island, I absolutely despised my time playing See Poochy Run! and I don't want to subject myself to that kind of torture ever again. If I'm forced to take screenshots of this level, I'll just try to find cheats for this level and play with them on.