Tropical amphibian of wormlike appearance. There are about 170 species known in the family Caeciliidae, forming the amphibian order Apoda (also known as Caecilia or Gymnophiona). Caecilians have a grooved skin that gives a 'segmented' appearance; they have no trace of limbs or pelvis. The body is 20–130 cm/8–50 in long, beige to black in colour. The eyes are very small and weak or blind. They eat insects and small worms. Some species bear live young, others lay eggs.

Caecilians live in burrows in damp ground in the tropical Americas, Africa, Asia, and the Seychelles Islands.

The African caecilian family Scolecomorphidae was found in 1996 to contain the first known vertebrate to be able to protrude its eyes. The eyes of Scolecomorphus kirkii are attached to the base of its tentacles, and when the tentacles are fully extended its eyes are carried beyond the skull.