Riking's post is not giving the new glitch the attention it deserves. Let's try again:
There is a new, game-annihilating glitch in Yoshi's Island that lets you put any sprite in your 'egg inventory' and bring it to any level!!!
It is discovered by Arne /
http://www.twitch.tv/arnethegreat and is called something like 'Null Egg Glitch'.
Carl Sagan did a testrun of what the real time route would look like using the glitch. The glitch is first set up here:
http://www.twitch.tv/carlsagan42/b/434004918?t=25m35s
The glitch is similar to glitches in Donkey Kong Country 1/2 where you are able to hold a despawned sprite slot and 'grab' the first sprite to take that slot.
The Null Egg Glitch is performed by grabbing an egg from a Mouser while it despawns from falling off screen. When it despawns, it despawns its egg, even though it is now in your inventory, so your inventory contains an sprite ID that is not assigned to any active sprite. Any sprite with that sprite ID that spawns is thus made part of your inventory.
In this RTA route, the glitch is used as follows:
1) Perform Null Egg Glitch on 2-2
2) So your game does not crash, put a skull-wearing Mouser in the sprite slot of your null egg before finishing the level
3) Go to 1-8 (Salvo's Castle) and enter Salvo's room with only one egg
4) Kill Salvo by throwing the egg, then spitting his babies back at him. Don't destroy any babies except by spitting them at him (I think this is part of the setup)
5) When the Key cutscene appears that signifies you've beaten a boss level, it uses the sprite ID of your null egg - meaning that the key cutscene sprite is part of your inventory!
6) Go to any level. The key cutscene will immediately start. Because it is very glitchy used in this way, you have to do different things to finish the level and make sure it does not crash. (You also have to position yoshi so he does not get eaten by a pirahna plant, or fall into lava, and you have to make sure you do not lose the key cutscene sprite, and some rooms crash if you do not enter a door or pipe)
You can also use the Null Egg Glitch to bring pretty much any sprite to any level with experimentation (for example, you can bring a submarine morph bubble to Salvo and ineffectually pelt him with rockets from your sky submarine, or you can turn your null egg into a pipe warp and warp to 1-1)
Another interesting use - the Null Egg Glitch allows you to achieve a score of 0 on many stages you could not before, as with the keyhole cutscene active you can lose mario but still finish the level at 0 stars. This means low% (get the minimum score on every level) can go much lower than ever before.
What's amusing about this is how many tiers of any% there are now:
1) any% (the glitched any% TAS on tasvideos)
2) any% no L+R (2-2%, arne%, keyhole%...)
3) any% no L+R/null egg glitch (any% warps)
4) any% no L+R/null egg glitch/wrong warps (any% warpless)
^ and walljumps can also either be banned or allowed on top of that.
But then it gets old really fast. In any case, I think Masterjun is working on an even more SMW-style glitched% run using other tricks Arnethegreat, the #yoshi IRC community, and I have discovered over the past year or so, and it would be substantially faster than using this null sprite glitch, suffice it to say.
That being said, there have been TONS of other glitches discovered since I published the last any% TAS that do not break the entire game in half, and are limited to just a level or two. I'm currently trying to plan how best to do a new any% TAS. The goal will probably be to beat the game as fast as possible while still grabbing a goal ring on every level.
