Leaf mimicry is the evolved resemblance of an organism to a leaf, a form of mimicry. This may serve directly as camouflage, or it may function as Batesian mimicry if the leaf model is distasteful, for example if it has chemical defences. The mimicking organism can be a plant, such as the vine Boquila trifoliolata, or an animal. It is not known how the vine can sense different leaf shapes. Among animals, many leaf mimics are insects, especially butterflies, katydids, and phasmids. Others are vertebrates, including leaffishes and toads. The mimicry, both in insects and among vertebrates, can involve behaviour as well as coloration and body shape.
Fossil leaf-mimicking insects are known from the Jurassic of northeastern China, including both grigs and lacewings, and from a phasmid of the Eocene of Germany.