I think I'm gonna try this. Sounds pretty fun.
I already do 3 sets of death crawls a couple days a week. Starts off in a standing position and crawls down into pushup position, only letting hands and feet touch the ground the whole time during the crawl. Do six pushups and then crawls back up to a stand in the same fashion. Pause and rest 5-10 seconds and crawl back down and do five pushups. Crawl back up. Repeat until you get down to one, then count back up to six from one.
I think I can already do about 50 straight. I'm still young though, so good luck to anyone with age against them.