No Mob Spawning on Trees Mod 1 8 9/1 7 10
Stop mob spawning on trees. Creepers will no more fall on your head. Especially useful if you have some mods which can generate big trees, such as Thaumcraft, ExtraBiomesXL, etc.
Download link: No Mob Spawning on Trees Mod 1.8.9/1.7.10