Is there such thing as a unicorn moth?

No, there is no such thing as a unicorn moth. Moths are insects in the order Lepidoptera. Moths are closely related to butterflies, although there are some key differences between the two. Moths are generally nocturnal, while butterflies are diurnal. Moths have antennae that are feathery or comb-like, while butterflies have antennae that are club-shaped. Moths have a wider thorax and a narrower abdomen than butterflies.