In minecraft it feels so blank for the sea just to be filled with water so I thought what it would be like if Mo'Creatures Mod worked in mutiplayer. I was thinking of fishes being added to the game only but it would be nice if there were an option for some animals to be turn off. DrZhark's Mo'Creatures Mod Edit: Oops I thought the post said what can a plugin do :[
this can't be made into a plugin because it has content that isn't in the original minecraft jar. you'll have to check if there is a multiplayer version on the mod's page.