13. Ribbon Worm
Although they look differnet and have different sizes, these worms have something in common: proboscis. Proboscis is a muscular structure found in the body of some worms, which is used to attack prey. Basically, the worm throws the proboscis outside and it catches the prey thanks to its ability of expanding. Whenever it’s in danger, the ribbon worm shrinks to one-tenth of its normal size, but it can also double its size to swallow fish, other worms, snails and even crustaceans. The length of the ribbon worms varies a lot and it can reach even 60 meters!