Mimicry is not something which is immediately associated with predatory insects. One tends to think of harmless insects mimicing predatory insects. However, the young nymphs of some mantids are clearly mimicing ants ar a way of reducing the risk of being eaten by other predators. The first instar nymphs of Odontomantis planiceps (de Haan, 1842) are a good example, unlike the older nymphs which are green, the first instar nymphs are black, and the have a body shape that resembles an ant.
First instar nymph of Odontomantis sp.
Orchid mantids, Hymenopus coronatus (Olivier, 1792), are members of the Family Hymenopodidae and mimic flowers. This is a rather twisted form of camouflage - camouflage usually involves staying hidden, but in this case the mantis is "camouflaged" by standing out in a bright colour- basically mimicing a flower. The objective is twofold: firstly to avoid being eaten by predators, and secondly, to attract potential prey who are looking to feed on the nectar or pollen of a flower.
A nymph of Hymenopus coronatus (Olivier, 1792). The adjacent bush had pink flowers.
Insects in the order Neuroptera, Family Mantispinae are easly mistaken for mantids. In fact insect dealers have been known to offer them for sale as mantids! The example below, from Borneo, was offered for sale by a dealer.