A Rotatick is a mob that spawns underground in the Overworld, in layers 25 and below, regardless of light level. The Rotatick has a long, slender, purple body that moves very fast. A common nickname to un-informed players is the "Caverpillar" due to its resemblance to a caterpillar and the fact that it dwells in caves. It deals 12 Points (x6) of damage and has 55 HP (x27.5), so caution is advised when this mob is present. Though they do massive amounts of damage to an unprepared player, they are relatively easy to kill with a Bloodgem Sword and can reward the player with up to 2 diamonds or Corrupted Shards.
It is advised to attack a Rotatick with at least a diamond sword and realmite armor.
When attacking a Rotatick, try to trap it in a corner and get the first strike to slow it down, as they are very fast moving.
If the player is unprepared, (without the proper armor/weapons) they should avoid Rotaticks as they are very powerful, fast, and have a high amount of health.