Actually this kinda come up in my ls the other day. We were talking about fighting a HUGE marmot as something kind of silly/different. Then I thought "Why not?". This would be almost a total rip off D2, but have a hidden marmot counter for each server. As you kill marmots the counter goes up and once it hits a certain number(or the more you kill after a certain number, an increased chance) you have this huge marmot spawn randomly in the areas around Grid, Uldah, or LL. Make it like a king marmot that's pissed off you've killed all the little ones. Personally I think this would be fun. You'd probably have a bunch of noobs yellin when it popped(why not have it pop in lowbie areas? lol) making it even more comical. You could even go as far as to have it pop after the death of a marmot in the same spot. This would lead to people xping for their first time, killing a rank 1 mob, and having a rank 50+ mob pop killing them. Kinda like my first time playing fallout 3, getting out of vault for the first time and running into a deathclaw.