EntityCreeper chargedCreeper = (EntityCreeper)MFRUtil.prepareMob(EntityCreeper.class, world);
NBTTagCompound creeperNBT = new NBTTagCompound();
chargedCreeper.writeToNBT(creeperNBT);
creeperNBT.setBoolean("powered", true);
creeperNBT.setShort("Fuse", (short)120);
chargedCreeper.readFromNBT(creeperNBT);
mobs.add(new RandomMob(chargedCreeper, 5));
EntityTNTPrimed armedTNT = (EntityTNTPrimed)MFRUtil.prepareMob(EntityTNTPrimed.class, world);
armedTNT.fuse = 120;
mobs.add(new RandomMob(armedTNT, 5));