Hookbill The Koopa's Castle

Hookbill the Koopa's Castle is the final level in World 4 of Super Mario World 2: Yoshi's Island. It was the home of Hookbill the Koopa until Kamek came and transformed him into a Gargantua Koopa Troopa in an attempt to slow down Yoshi.

Overview
Blue Yoshi starts in a long corridor with Boo Guys, and a Bucket hanging on the ceiling. After this corridor, Yoshi has to use a bridge to across a lava pool, with a Hot Lips trying to harm Yoshi by spitting lava at him. Yoshi also finds Koopa Troopas here, and he can use their shells to reach a Flower right above the lava. Not only Koopa Troopas and Hot Lips try to harm Yoshi, but Boo Guys opering Maces also try to slow down him. After the second Hot Lips, Yoshi can use another shell to collect a Flower above the lava. Yoshi also finds another bucket, and a pipe spawning Boo Guys here. After the lava pool, the dinosaur needs to cross a long corridor, with Boo Guys trying to crush him with Maces. Yoshi must destroy large blocks with eggs here, allowing him to reach a Door. This door leads to a room, with ? Clouds that form stairs when hit, and several Boo Guys opering maces. He can also collect Red Coins here, as well as a Flower by passing through the One-Way Flippers. Upon entering the door, Yoshi finds an Arrow Lift, which he must use to across a large area with Thorns, and reach a locked door. He can also use this Arrow Lift to reach a Bonus Area in the ceiling, where he must defeat two Large Mildes to earn a single Red Coin. In order to unlock the door, Yoshi must hit a ? Cloud in a narrow corridor using a Shell, thus making a stair appear. Yoshi must then use this stair to reach another door. Here, Yoshi must ground pound a Crate containing the key. Then, he must simply pass through the One-Way Flippers to make his way back to the area with the locked door. After entering this door, Yoshi needs to climb a tower, while avoiding the Fishin' Lakitu that tries to steal Baby Mario with its hook. Once he reaches the top, he must enter a Warp Pipe, leading to an area with several rectangular blocks, which can be destroyed by throwing eggs at them. There are two Flowers along this blocks. By destroying one of them, Yoshi is able to use a trampoline to reach the red door leading to the boss.