Still needs a different concept in my opinion. If it looked the same, and did the same thing, you would have only as much fun as you might with regular creepers in Minecraft. It's like requesting an M-16 or a Famas on this forum - it's something that already exists. You might get bored soon after playing with it because you:
A) Already did most of those things in Minecraft.
B) As a result of A, quickly run out of ideas for it in Blockland.
This needs a new model, a new concept such as it may be invisible or disguise itself as annother player on a server until it comes close enough, preferably 12 studs, when then *poof* it's a creeper. It then runs a little faster at you and blows up. I think the current "SSSsss" sound is fine, and it should make it when it starts its charge.