Dancing Shelly

You may be looking for the Hybrid version.

The Dancing Shelly was a special type of Shelly that is found on the Ice Island. It had an absurdly high amount of health, capping at 999,999,999 health. The mob dropped one God Bag, prior to its patch, when killed, but this was entirely useless as you could not pick up the bag after the patch.

Location
It was found on the Ice Island, with no specific location given. It had the appearance of a normal Stone Shelly, with the exception of its name and health. It would spin in circles. There are many ways to mine this and do it fast.
 * 1) Grab 3 mammoths (the capacity since they might bite each other) and surround it and keep them there.
 * 2) Grab 3 friends (the capacity since you might accidentally attack/damage your friends)then keep continuously mining.
 * 3) Use the quick switching click glitch (basically if a player switch between a weapon after the user have used another, there is no "use" delay when the player switch to another weapon, thus doing more damage in a short amount of time.
 * 4) Use autoclicker and the glitch
 * 5) Use autoclicker and a keyboard key auto presser and the glitch (Program the auto presser to spam press 1 2 3 4 5 6 as those are the easy access to using tools and weapons currently located in the player's tool inventory, beginner rock)

Drops

 * Needed

Trivia

 * It is the only mob to have health surpassing 100,000 hit points.
 * There have been many users that have been known to legitimately kill this mob (ie. without hacks) in the past; Airtroys, OP_aw3s0m3r3c068790, ek6359, AbleDiamondGamer, skirmish_boii, IgneousCorn, noobBmaniababy and JakeAdminDoni.
 * As of the Storm Update, this Shelly now spins in place, staying to its name "Dancing Shelly".
 * The Shelly could be damaged by a mammoth, as its spinning nature would cause it to constantly get hit.
 * The Dancing Shelly is probably a joke mob left in the game by the developer, Soybeen.
 * The Dancing Shelly was removed in the ??? Update, then later was re-added in the Map Legacy Update.
 * Similar to the Spirit Shelly, this will not retreat into its shell when damaged.
 * Despite spawning in the snow biome, it has no arctic texture or color, looking just like a normal stone Shelly.
 * It can be mined with any Pickaxe in the game. This is probably because the Dancing Shelly was intended to be a joke mob.
 * MarcoTheTalonflame discovered a glitch to kill the Dancing Shelly in minutes by placing chest on it so it glitched out of the map.
 * Prior to the God Bag's introduction, the Dancing Shelly would initially only drop a Stick (early version of Wood), but would later be updated to drop a Berry.
 * It is has been confirmed to first: drop a stick, then a stone, then a berry, then a god bag. All these droppings have been removed, and it is still uncertain what it drops now.