(Yes I still own a original Gameboy and Pokemon Red) So, basically, in a nutshell, I’d successfully obtained a MissingNo. and had it on my team for about a month now -Now the for the confusing part- so today I when on and saw that my (Shiny(I 95% think so)) Charizard has disappeared somehow and I still had my MissingNo. This hasn’t happened before hand and I haven't hacked it... Why did it happen?!
Pokemon Red And Blue Mechs Are Really Wack so lets just say this:
You can use these Mechanics in red and blue and yellow to make wild Pokemon appear that can only be obtainable threw trade some of these Pokemon I know you can get from these types of mechanics are alakazam golem and some more I forgot them but the reason why your charizard is gone its because of gen 1 mechanics so just blame that Hope This Help!