Toloa is a constellation in the sky, also known by its name copied from English: the Southern cross (Crux). But in the Tongan mind the stars of the cross rather outline a duck flying over to the south.
In the myth of the both Maʻafu, the duck was a wild bird, but was caught by the twins, and later together with Humu and them placed in the sky. In another myth the western wing of Toloa is wounded because Two men threw stones at it. The star on that spot is fainter than the others.
When not in the sky, Toloa and Humu are still two good friends. FOKI