I'm going to take over a Dungeons and Dragons group from someone
Can you tell me why you decided to take over that group?
I'm going to call the new group Fast Zombie Dragons.
Tabletop groups are a tight knit community and trying to usurp the leadership of one is very rude and inappropriate social behavior. You will likely be ostracized from playing DnD once word gets around of your behavior. If you want to lead your own group as dungeon master, try forming a new one rather than taking over someone else's group.
What? They will be amazed that I created a new way to play DnD.
No they won't. People don't like when you change the rules of their game all of a sudden. And they especially won't appreciate you doing it when taking over a group.