The Goatpedia is the in-game encyclopaedia that contains images, size information, coin per second statistics and brief descriptions about the goats. Entries are unlocked as each creature is mutated. The game needs to be rest several times to unlock all of the entries.
Each of the goats will be listed below in the order they appear in the Goatpedia, with the arrows showing how they mutate. Note that when the Universe is reset alternate goats are available, in place of the final goat of each stage - these are listed under alternate for ease of viewing.
(The individual pages are being updated periodically as people play through the game)