There's this one guy on the Nuzlocke forums, Zowayix, who has so much knowledge about data and percentage (not to mention a lot of ******* persistence) that he actually used the Mew glitch to fill up his 'Dex without trading. That's impressive.
There's one guy on Youtube, who has made a whole series called "Let's Glitch Pokemon Yellow". He's shown all the glitches of the first gen and even explained, what they do and which one of them are dangerous to your game, etc. He also created a Magikarp whith Fly and a Pikachu which knows Surf.
Most of these are origined by the Mew/Ditto Glitch.
Yeah, in that regard, Poison is kind of imbalanced. In fact, the most common Poison move in competitive is Toxic. Followed closely by Toxic Spikes. See? It's so useless in combat people don't use it in combat. Would be boss if it became like the one of two ways to take out fairies.