Spineback Worms dig throughout the grounds of the Vethea. Their means of transportation is just moving quickly through ground and tunneling out in order to attack a player. They will attempt to surprise a player from above or under the ground at any time. There is a stonger, bosslike version of this known as the Spinaraus.
Spineback Worms have large amounts of health, however this does not mean avoiding them is the best tactic. This mob will follow a player elusively if he is seen by the Spineback Worms.