Caecilians
Caecilians are often mistaken for eels or earthworms. These tropical amphibians do not have legs or a tail. Most caecilians have poor eyesight and some lack eyes completely. Instead these amphibians have a groove on either side of their head that contains a tentacle that is used to detect their surroundings. Caecilians posses a Jacobsen's organ much like snakes and some lizards which helps process the information form their tentacle.
Caecilians all require a moist area and there are some that are fully aquatic. The terrestrial caecilians are burrowing animals and are often not seen in the wild because they are burrowing underground in swampy areas. Burrowing caecilians have developed a compacted head that is excellent for digging.