ExtraTricky, just to clarify, the way you handled missingno is that you 1): growled, 2): healed, 3): Missingno attacked, and healed again, 4): Leach seed, 5): Tackle, and 6): Growl, and then catch. Also is the catch not guaranteed (like in Yellow)?

i think you talk about death fly stats or skipping 1 T-Fly, important is that your healing items are in slot one, when you can heal you need too heel twice indeed, once you catch it you have 255 potions, the rest of the menu's are the same. Missingo is in pokemon Blue redicilously difficult too catch. his catch rate is damn low so yeah goodluck grinding it out OpieOP

SIde note, before you encounter missingno make sure you only have 1 Potion.