Sluggy The Unshaven's Fort

Sluggy The Unshaven's Fort is the fortress level of World 5 in Super Mario World 2: Yoshi's Island and Yoshi's Island: Super Mario Advance 3. This level's playable Yoshi is the yellow Yoshi.

The fort features many spikes and moving platforms, a large viscous creature known as a Support Ghost that carries a Flatbed Ferry on its head, and an unusual spinning platform which functions much like a Chomp Rock on a track. The titular enemy of the fort, the Sluggy, is a small hairy slug enemy which can be found throughout the level, in two colors of off-white, slightly red and slightly blue. These slugs habitually fall off the ceiling onto Yoshi. Another notable slime is a Georgette Jelly, a pudding-like goo which falls to pieces if trod upon, but regenerates again after a few moments. These slimes can be swallowed and spit out as a bouncing ball.

The level is also populated with Dangling Ghosts, large ghosts which cling to the ceiling and swing back and forth like a pendulum. When Yoshi gets too close, the ghost grabs Mario off his back, and retract. When the ceiling is too high, Yoshi is unable to reach him. However, hanging ghosts on high ceilings cannot reach all the way to the floor, so it can sometimes be safe to crouch under them. The pendulum slimes can be made to stay still by being shot with an egg or having an enemy spit at them.

The level also has the only normal Chain Chomp in the game.

Overview
At the start, the player is between a pendulum slime and a door. The door, to the left, leads to a room which is empty except for a Chain Chomp. Destroying the Chain Chomp reveals a secret door, leading to a Message Block with a secret message from the Mario Team to hold, and press , , , , (, , , ,  in Yoshi's Island: Super Mario Advance 3) at the level select screen. Yoshi should shoot eggs at the slime to the right in order to pass.

Not too far ahead is a very large, yellow platform that Yoshi can go across and get eggs, unless the platform were blocked off by stairs. This is the first of several times in the level where popping a Winged Cloud creates a staircase blocks off some area. However, it is possible to carefully walk past the first step of the stairs in order to get to the inaccessible area; jump while sanding at the base of the stairs, and press right (or left) at just the right moment. An alternative is to find a pipe or door to go through and come back, resetting the stairs so they haven't been made yet. Getting past this first staircase is a good idea because after the block of slime there is an invisible Winged Cloud (just under the Fangs). The cloud yields some extra Stars.

Once Yoshi goes up those stairs, he should jump leftward off of them to collect a Red Coin, then continue left to retrieve a Special Flower dangerously buried amid spikes. Bring plenty of eggs in order to get it. Then return to the stairs and travel to the right, avoiding spikes and enemies on the way. There is a tube which Yoshi can go down. Kill all the Sluggies there to get a Special Flower. Next, there is a Red Coin in the ceiling behind a breakable block. Then a yellow platform takes Yoshi over a bed of spikes, but not through the Red Coins hanging there. A round platform takes Yoshi back over the spikes, grabbing Red Coins on the way. This platform should be used like a Chomp Rock, constantly moving Yoshi to remain on top.

Next is a single egg between two Winged Clouds, each of which creates a staircase and blocks the creation of the other staircase. The staircase leading to the upper left brings Yoshi to three coins and the Middle Ring. It is a shortcut, which the player cannot take if he wishes to retrieve all the red coins. It is fine to create this staircase and collect the coins, but then use the trick described above to get past it's bottom step and backtrack a little in the level, to a tube Yoshi can go in. Come back out and create the staircase which goes upwards and to the right instead. Then it is possible to jump over to the left. After evading a hanging slime, break some blocks open with eggs to find some extra Stars, and proceed to the left.

There is soon be a choice between two directions, a Red Coin lying in each. Grab both coins before making the choice. The drop to the left leads to a brief adventure with a slime which allows Yoshi to walk over spikes in order to retrieve some coins. Pressing down removes the slime from Yoshi's feet, so be careful not to press down over spikes. Going to the right instead similarly leads to many coins. Neither option leads to Red Coins, so it doesn't matter much. Shortly, Yoshi arrives at the same Middle Ring which the earlier shortcut stairs led to, but two Red Coins richer.

Farther in the level, Yoshi and Baby Mario finds a Support Ghost that can move right, up, and down and must ride him to the red door at the end. Sometimes he stops and stretch his up body for Yoshi to reach higher areas. But not long after, he goes back down and if Yoshi is not on the platform on the Support Ghost when he moves away, he is stranded. Later, Yoshi is in a tight and long room filled with miniature Sluggy enemies. Once Yoshi squeezes through, he goes through a door leading to Sluggy, whom he can beat by hitting his heart a few times.

Trivia

 * This is one of only two fortresses in the game to feature the "Room Before Boss" music, the other being Bigger Boo's Fort.