I've always liked the idea of Magikarp being a sort of TRAP that evolves into Gyarados, but I wonder if it would really work out. After happening once, you're just going to run away from it. I was thinking it should have AI to FOLLOW YOU to try and put itself in HARM'S WAY, but that would make you want to run from it EVEN MORE. Maybe it should hop around away from you some, and then hop toward you, in a sort of OFF AN ON PATTERN to make one feel less TARGETED.
Or just hop around randomly. I guess that works too.
...Also, it's pretty funny that they didn't even get Munchlax to say it's English name in the English version. TRUE STORY: In an online match I had with some friends, I guess Pokeballs were on high for the occasion, and I kid you not, every single one of them had Munchlax in them. "Okay, who turned Munchlax on high?" I shall never forget that quote.