Rock Pet

The Rock Pet is a Mining Mount that drops directly from mining. Unlike most other pets, the Rock is obtained via milestones, similarly to the Dolphin Pet.

How to Obtain
The Rock Pet is obtained by reaching ore mining milestones. The milestones are as follows:

Note: To obtain the pet, players must mine a certain amount of ores. Blocks such as stone, netherrack, and end stone do not count towards the total. While players cannot see their progress toward the Rock Pet in-game, their progress can be retrieved from SkyBlock API. A good representation of the player's progress can be found at the SkyBlock Stats Website (sky.lea.moe) in the miscellaneous section.

Kat Caretaking Costs
Kat can upgrade all rarities of this pet except legendary; this costs varying amounts of money and sometimes resources. For each level the pet has, there is a 0.3% discount. For example, at level 50 there will be a 15% discount to the price listed below. Also, the cost listed is for the pet of that type to be upgraded, after which time the rarity will be that of the above type. The time listed is also in real life days as opposed to the in-game equivalent.

Trivia

 * Any ores mined can spawn the Rock Pet. This can be on a private island (if the ores were placed by a minion), in the Coal Mine, at the Gold Mine, in any layer of the Deep Caverns, and even The Park (gold ore spawns in the Savanna Woodland caves, although mining for a pet here is not recommended because of the low quantity of ores).
 * Though unconfirmed, using a pickaxe with the smelting touch enchantment can glitch the drop of the rock pet.
 * While riding the rock pet, the player takes no knockback. This can be useful for Slayer quests.
 * When sneaking at the edge of a block the Rock Pet will fall down. Jumping after it and right-clicking it mid-air makes the player sit in the air not moving as the Rock Pet glitches away.
 * The rock pet is the first pet to have more than one skin in a Fire Sale
 * You can mine ores to upgrade the pet, though this is way less efficient than upgrading it through Kat. This is the same case as the Dolphin pet.
 * There has been a bug involving using the Rock Pet and right clicking with an item with an item ability. This would cause the player to be bugged and be able to walk around, break blocks, and place blocks, all while still being on the rock pet on other player's screens. However, this appears to just be an visual bug, as other players still see the player on the rock pet. This bug was shown through a Dragonhanx youtube video.