I think the mobs should be upgraded to make them better.
Skeleton - If the skeleton dies, it would explode ( not a creeper explosion or something like that) and arrows will be shot everywhere that can hit you. It will still drop the resource it usually drops.
Spiders - If you encounter a spider, it will shoot spider webs at you, making you slow down a bit.
Zombies - Since their attack is very weak and slow, they should have a helmet and/or chestplate equipped with them so they will be stronger. If you managed to kill an armored zombie, it will only drop the feathers that it usually drops.
Creepers - They get super charged when hit by lightning. If they get hit by lightning, you will see a it glowing and it emits an electric sound to make them more obvious to see/hear.
Squid - If you get near one, it will spray ink on you and make the water much more foggy.
Sheep - If they get hit by lightning, they will be set on fire and leave a trail of fire as it walks
In SMP, if a player gets killed by lightning, he/she will be turned into a zombie with the armor still on. It will also drop everything else except what it is currently holding.
Skeleton - If the skeleton dies, it would explode ( not a creeper explosion or something like that) and arrows will be shot everywhere that can hit you. It will still drop the resource it usually drops.
Spiders - If you encounter a spider, it will shoot spider webs at you, making you slow down a bit.
Zombies - Since their attack is very weak and slow, they should have a helmet and/or chestplate equipped with them so they will be stronger. If you managed to kill an armored zombie, it will only drop the feathers that it usually drops.
Creepers - They get super charged when hit by lightning. If they get hit by lightning, you will see a it glowing and it emits an electric sound to make them more obvious to see/hear.
Squid - If you get near one, it will spray ink on you and make the water much more foggy.
Sheep - If they get hit by lightning, they will be set on fire and leave a trail of fire as it walks
In SMP, if a player gets killed by lightning, he/she will be turned into a zombie with the armor still on. It will also drop everything else except what it is currently holding.
I think this thread is just about stronger varieties of mobs, not lightning transformations. I did make a thread about that, though...
Hard mode: yes
Easy mode: no
I for one am not a monster slayer so having them do more things then they already can would quickly overwhelm me.
Wraiths: Boss-like mob for Hard!