There is an equal chance to receive each companion.
Before update 2.14 Edit
Prior to the 2.14 updates, companions could also be received by purchasing them in the gear menu. The companion that was available for purchase was random with a random price in a range based on the material.
Prices of 20, 30, 40, 50, 60, 70, or 80 Edit
Prices of 200, 300, 400, 500, 600, 700, or 800 Edit
Dirt, Wood, Clay, Sand, Sandstone, Cactus, Ice, Snow, Gravel, Stone, Coal, Iron, Redstone, Lapis Lazuli, Bedrock, Obsidian, Netherrack, Soul Sand, Nether Brick, Nether Quartz, Glowstone Dust, Red Sand, Red Sandstone, Hardened Clay, Orchid Seeds, Coffee Beans, Dandelion Seeds, Jungle Log, Podzol, Sponge, Coral, Live Rock, Moon Rock, Aluminum, and Diorite
Not Tradable Edit
- Most all of the rare blocks have prices between 20 and 80. The exception is Bedrock, making it a common obstacle when massing companions.
- Most of the untradeable items are unique by either only being available during events, not obtainable from a block, or extremely rare. Lunar Meteorite does not possess any of those properties, so its reason for not being tradable is unknown.