It's called lagging...you need no hack to perform this
Okay so what I've been thinking of is sort of a Blink exploit. (Incase you didnt know, Blink is a exploit in Minecraft where you stop movement packets and send them)
Anyways, would it be possible to stop movement packets, but log them and then send the packets you just logged all at once? Not sure if this is possible but... You know :P
It's called lagging...you need no hack to perform this