World 6-8 (Super Mario Bros. 3)
From the Super Mario Wiki
Unlike most of the levels in Ice Land, this level is grassy. It starts with five Ice Blocks, a ? Block with a Super Leaf, and a Ptooie. After this there is a single Koopa Troopa, Walking Piranhas, and Spikes. After this there is another ? Block with a Super Leaf, surrounded by Ice Blocks. After this there is a Buster Beetle and Ice Blocks in the shape of the letter H. On top of them, there is an Hidden Block with an 1-Up Mushroom. After that, there are more Walking Piranhas, another Buster Beetle, and a ? Block with a Switch Block. On top of the Switch Block, there are many Brick Blocks, and after this is the goal.