This post is from a low-reputation account and contains an unverified outbound link. Be cautious before clicking external links.
Another ocean dweller to be wary of is the cone snail. It may not look like much, and you may easily mistake it for any other snail on the beach, but it is extremely deadly. Just one drop of its venom can kill twenty human adults. There is no antivenin, which means that if you are stung, you will almost certainly be dead within minutes
source by:http://www.conservationinstitute.org/top-10-dangerous-animals-in-the-world