No, a butterfly is not a mammal. Butterflies belong to the class Insecta, which makes them insects. Mammals, on the other hand, are in the class Mammalia.
Butterflies go through a life cycle that includes four stages: egg, larva (caterpillar), pupa (chrysalis), and adult. They are characterized by their colorful wings and are known for their ability to fly. Mammals, conversely, are warm-blooded vertebrates that typically have hair or fur and produce milk to nourish their young.
In summary, butterflies and mammals are distinct groups of animals with very different characteristics and biological classifications.