Glitches are typical in video games. Some are rather famous and others that are quite fun to play around with. The Pokemon series has such well-known glitches such as Missingno. and the Cloning glitch. I haven't seen any thread like this one, so I thought to myself “Why not?”. The title says it all: What is your favourite glitch in the Pokemon games?
I haven't checked out all of the glitches yet, but one of my favourites is the Mimic Glitch. I once considered doing that glitch, because having Pokemon with illegal moves (e.g., Flareon with Flare Blitz) sounds quite fun. It occurs on D/P/Pt, in case you're curious.
Another one that I find rather amusing is you can use Surf on a tree in Black 2/White 2. The tree is located at Pokestar Studios.
You can also tell me any glitch stories too. I've got one in mind. I was doing a HeartGold Nuzlocke, getting ready to grind. But just as I was about to, I somehow managed to tweak the game, and it ended up freezing.