Euthaliaaconthea, the common baron often called simply baron, is a medium sized nymphalid butterfly native to India and South-East Asia. It flies with stiff wing beats and often glides. The wing is not flapped very far below the horizontal. Common baron caterpillar hatches into a mud-colored butterfly. This butterfly causes itching if touched.

The Common Baron (Euthalia aconthea) is a medium-sized butterfly with a subtle, earthy-toned appearance, commonly found in South and Southeast Asia. The male and female butterflies exhibit sexual dimorphism, meaning they have different appearances.

Common Barons are typically found in gardens, forests, and near human settlements. They are known for their swift, strong flight and can be seen feeding on rotting fruits and tree sap. The caterpillars of the Common Baron are green with spines and feed on Mangifera indica (mango) leaves, making this butterfly a pest in some mango-growing regions.