Wallago attu, boal, or helicopter catfish, is a species of freshwater catfish of the family Siluridae, native to South and Southeast Asia. W. attu is found in large rivers and lakes in two geographically disconnected regions (disjunct distribution), with one population living over much of the Indian Subcontinent and the other in parts of Southeast Asia. This species can reach a length up to 1.1 m (3 ft 7 in).

It shares parts of its native range with the externally similar, but much larger Wallagonia leerii, and is subsequently often confused for it. It can, however, be differentiated by its relatively long and narrower head, as well as its dorsal fin, which is high and sharp, opposed to that of W. leerii, which is lower and rounded. Additionally, the eyes of W. attu lie above the mouth of the fish, whilst they lie on the same level as the mouth in W. leerii.

This catfish is one of the fish species that has been used as food in Southeast Asia since ancient times. In Thailand, its meat is popularly used to make thot man (ทอดมัน, "Thai fish cakes"), similar to clown featherback (Chitala ornata).

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