No more rocks, have a pink dingus instead

Monster Codex: The Doppelgänger
The doppelgänger is a creature to be feared. This is due to their ability to shapeshift to mimic a person. They typically do this to invoke fear, which they feed on.
Encountering your own doppelgänger is said to be a bad omen, with tragedy following shortly after. This could be cherished possessions being broken, personal relationships falling apart or even death. It is unknown how the doppelgänger causes these unfortunate events nor how to prevent them from occurring once the doppelgänger has been seen.
Overall, doppelgängers are difficult to document as they prove to be elusive in nature. The true form of a doppelgänger is one of nature's greatest mysteries. Because of this, the image below depicts what a doppelgänger might look like without a disguise based on brief glimpses by witnesses. This depiction is not to be taken as an accurate depict

Monster Codex: The Selkie
Selkies are aquatic shapeshifters that take the form of a seal when in the water, and the form of a human when on land. Unlike werewolves, this is a voluntary process and can be done whenever the selkie chooses. They typically take the form of a grey seal (Halicoerus grypus), however selkies that transform into other pinniped species have been recorded.
Selkies are affectionate creatures, both as seals and as people, and enjoy playing with whatever they come across. There are very few reports of selkies attacking humans unless provoked. This affection has led to the selkie being taken in by humans, which can be stressful for the selkie as it wishes to freely roam the ocean.
One can tell a selkie in human form from a true human by their hair, which is the same colour as their seal form, and by their seal-like eyes.

