User blog comment:AStranger195/Can you do what I can do?/@comment-4546491-20130419141904/@comment-5792287-20130419154725

I, Zombie 100 would have to be either via hacking, or use of this Bungee Trick, which usually requires the speedhack anyway.

Note: You can do that Bungee Trick on the Xbox 360 without hacking, so that may be how to get to 100 in I, Zombie Endless without hacks.