An otter attempts to make a meal of a pufferfish in this video. This National Geographic video shows the fish using its famed balloon technique to inflate its body. The otter eventually gives up on the fish and swims away. Had the otter succeeded in eating the pufferfish, it probably would been a fatal mistake. National Geographic says most pufferfish contain the deadly poison tetrodotoxin, which is up to 1,200 times more poisonous than cyanide.