5. Blue Ringed Octopus

About the size of a golf ball, do not let its small stature fool you, this hazardous creature retains enough venom to kill 26 full-grown adults. As you might have guessed, there isn’t any antidote. Assuming your friend gets bitten you’d better understand CPR since you may be confident that within minutes they will be totally paralyzed and not able to breathe. The effects will continue for a few hours before the venom is neutralized by their own entire body. That is of course assuming that you, or somebody in the hospital, succeeds with artificial respiration.