When a charged creeper explodes next to a creeper in vanilla your supposed to get a Creeper Head, But with the mod since creepers don't damage other creeper it isn't possible. It would be fine if creepers did like two hearts to each other.

i don't have the time to merge / publish a full fabrication release right now.
if you wish you can tell me which version your on and i'll try taking the time for a single release.