Super Mario World Glitches
This article contains every glitch I know of in the SNES game, Super Mario World.
Be warned, this is a very long list. :3
It is possible to regenerate a P-switch with the use of Yoshi. After hitting a P-switch, immediately have Yoshi eat the flattened remains. The game will register the remains as a P-switch, and make that the item Yoshi has in his mouth.
It is also a glitch that if a silver P-switch is taken through a pipe, it will act as a blue P-switch rather than a Silver one.
Placing two carryable items, such as a shell, key, p-switch, etc. closes enough to each other on the same square and running towards them and grabbing them correctly, will allow Mario to carry both items.
If Mario kicks an item like a shell up close to a vine, and then grabs the vine while holding X or Y, Mario can hold the item he just kicked up.
The Blue blocks that Mario can pick up and kick around will never disappear if it is taken through a pipe. Best done in Valley of Bowser 2.
Mario can jump off of a key while in the air by pressing B and Y almost at the same time while on the key. Doing this will cause Mario to pick up the key right as he jumps. This can be done multiple times while in the air. This can also be done with Blue Pick-up blocks.
Kicking an Item into a block and hitting it with Mario's head in a very fast rapid succession can spawn more blocks that can have different contents based on where they were spawned.
If Yoshi eats an item as it is coming out of a block, like a mushroom or Fire Flower, the game won't register it as a complete sprite, thus, Mario will not receive the power-up.
If an item such as a key or shell is position correctly under Yoshi, Mario can jump on Yoshi, and carry the item. In this way, Yoshi won't need to have the item in his mouth, and pose risk of swallowing it.
In Star World 4, if Yoshi eats the key, flies to the left and hits every Green Switch Block, and collects every feather, the game glitches the key. Spit it out by the shell kicking koopa, and it is a weird spinning glitch sprite that doesn't hurt Mario, nor can Mario hurt it. If Yoshi eats it, it acts as a feather.
In Donut Plains 1, there is a Question-mark block with a Yoshi in it, and a Super Koopa by it. Hitting the block at the same moment the Super Koopa hits you will spawn a Yoshi as normal. It has a small sound glitch before jumping on it. and if Mario drops Yoshi down a hole, the block Yoshi spawned from will have another Yoshi waiting for him.
position Yoshi under a berry as fire or cape Mario (with a cape of fire flower in reserve respectively) Yoshi can freeze the screen. Mario has to jump on Yoshi right as he collects the new power-up. Doing this, Eating the berry, collecting the power-up, mounting Yoshi, and loading the drum sounds while on Yoshi all trigger at once, freezing the level.
However, if Mario has beaten the level, pressing Start and Select can exit the level.
If a baby Yoshi eats 2 enemies/berries very quickly, it will count as 3. Doing this can make getting a full-grown Yoshi much quicker.
Lakitu's cloud will never disappear if Mario kills the Lakitu with a fireball and collects the generated coin. If Mario presses left and right on the D-pad with rapid succession while in the cloud, Mario can move through walls. while riding it.
In the level Forest of Illusion, a little ways past the midway point, there are floating logs with wigglers on them. Repeatedly jumping from one wiggler to the other, letting the last one you hit go off screen causes Mario to gain multiple lives, which eventually appear as glitched characters, coins, and almost a million points per jump as more wigglers are jumped on. YOU MUST HAVE THE WIGGLERS GO OFF SCREEN SO THEY CAN RETURN TO THEIR YELLOW FORM, OTHERWISE THE GLITCH WON'T WORK. This is made easier with a cape.
On Iggy and Larry's boss platforms, if Mario presses down and slides into one of their fireball attacks, it will act as if it's killed, and give a glitched graphic. This can also be done in the Forest Fortress by sliding down the small triangles used to run up walls, and hitting a Grinder saw.
If Mario jumps into a wall while moving running fast enough, he can hit A or B right as he collides with the object, and thus, "wall jump".
Putting an Item on a pipe that extends up and down will cause the Item to get stuck inside the pipe.
In the stage Funky, have Yoshi, and let the timer go below 100. The music will speed up. Eat a green berry, and the time will go back above 100, and once it goes below 100, the music will speed up again.
With a cape, spin jump on a large area of turn blocks while mashing Y and holding left or right on the D-pad. if done correctly, you can move so fast, you can end up moving through walls. This is best done on Star World 1.
In Donut Secret 1, enter the pipe that leads to a vertical area with a P-balloon. Note that the pipes are orange. Once you get the balloon and got up the level a large ways, and get back down, the pipe should be green. Going up specific amounts can make the pipes turn green only half way at times.
If you hit a Question-Mark block that has a coin literally on the tile right above it, an invisible block will spawn above the question-mark block.
If Mario enters a pipe at the exact frame he gets hit, the game doesn't load the hit animation for Mario, and when he comes out of the pipe, he will be small.
If Mario enters a door or pipe on the frame he is killed, he will survive, and the area Mario enters will have the Death sound instead of music.