Lucky Block by Player In Distress
http://www.planetminecraft.com/mod/lucky-block/
Mowzie's Mobs by BobMowzie
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/2361125-mowzies-mobs-fantastical-mobs-for-your-mc-world
OreSpawn by TheyCallMeDanger
http://www.orespawn.com/download-17.html
Mutant Creatures by thehippomaster21
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1284438-mutant-creatures-updated-v1-4-8
Better Dungeons aka Chocolate Quest by Chocolatin
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1278075-chocolate-quest-mods-for-the-adventurers