As an expert in the field of comic book lore and superhero abilities, I can tell you that Mystique, a character from the X-Men universe, is known for her shape-shifting abilities. However, her powers are typically limited to transforming into other humanoid forms, not animals. She can mimic the appearance, voice, and even some of the physical attributes of the person she is copying. While she has demonstrated the ability to alter her form to a certain extent, such as elongating her neck or changing the shape of her limbs, she does not have the power to transform into non-humanoid creatures like animals.

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The Wikipedia notes that she can: Mystique is a mutant shapeshifter with the ability to psionically shift the formation of her biological cells at will to change her appearance and thereby assume the form of other humans and animals.read more >>