Glitch pokemon
MissingNo is a glitch pokemon from the pokemon gen 1 games that will activate if you talk to the old man which teaches u how to catch a pokemon, then go to the wild area and missingno will appear, catching this backwards L with a glitchy texture will make your game lag and glitch out the textures of the pokemon and a trainer when battled (Sometimes, this only happens when Missingno lands an attack), and this thing isn't worth catching because it's bad.
2. No-start bug
This bug occurs on scratch, it rarely does happen though, but I got it on 2 of my games, I managed to fix the 2nd one, while the 1st one, I had to completely delete it. So this is what happens if you get this bug, every time to press the green flag, everything will, not happen, and will freeze in place without doing the scripts it's supposed to do. However you can fix this bug by doing when green flag clicked -> broadcast [whatever message you wanna put lol] and then replace the scripts where the green flag needs to be clicked in order for it to happen to when I receive [whatever message you wanna put lol], and attach the rest of your sprites's scripts to that and yeah, it should work by now. And also the "2nd game" that got infected was this bug was unfortunately the game that most of you liked, this one. But I did fix it fortunately and you guys could play it normally now, I re-tested it many times and it still worked!