This is more of a nonfiction piece considering how I could get inside (and back out) of some of the only animals that could probably swallow me whole. Keep in mind that only one of these is actually if genetic engineering/shrink(grow) rays/etc. fictitious stuff were used. If you see any errors in my judgement of some things, or if I forgot a particular aspect of something, or if you'd like to suggest I try it for another animal, please contact me through PM.
Anaconda (of appropriate size; likely 4.5 inches or more in width of head): I’ll need a whole nother submission for that, because I have so many ideas and stuff that I'd have to put in action.
Crocodile (would have to be very large, might not work, have to be at least 4 times longer than me): somehow I’d have to catch one, and whether I had the means, money, and legality or not, I’d either have to be eaten there where it was caught, or take it home or away somewhere with a cage suitable. Then I’d