player_03
P3
After Yoshi's double jump, he goes into this animation until he stops rising. Normally he hits the apex of his jump and goes into his falling animation, but if he lands on a slope, the slope can continue to push him up. You'd think he'd land when he touched the ground, but no, apparently this animation takes precedence.
During this animation, Yoshi can't attack, jump, or dodge. All he can do is control his horizontal speed, to try to land sooner.
This works on any slope in the game, no matter how small. As long as Yoshi is moving upwards at all, he doesn't land.