Depictions of Ewi (mudfish) are among the most frequent motifs in the Emwin Arhe (royal treasures). Mudfish hold an important place in Edo belief, both as representations of the god Olokun and as symbols of royalty (Plankensteiner 2007, p. 410), as well as of “prosperity, peace, well-being and fertility” (Ben-Amos 1976, p. 245). Mudfish are also particularly common animals for sacrifice, and mudfish-shaped Orhiẹvbẹ (kola-nut boxes) were used to make offerings or store kola nuts.

Yet, the appearance of Ewi across the Emwin Arhe is not consistent, and it has been argued that different species of mudfish were depicted by Edo artists, each with different qualities and capabilities. For example, the electric shock of Malapterurus electricus resembles the fierceness of the Ọba, while the liminal qualities of the Synodontis clarias mudfish, which lives both on land and in water, similarly reflect the Ọba’s rule over land and sea (Gallagher 1983, p. 93). With these different qualities in mind, the mudfish is an important symbol of Benin kingship and royalty.

Sometimes the Ọba was depicted by artists with mudfish rather than legs (see Ọba with Mudfish Legs).

According to , this motif is known as Aghadaghada, a “play on the word ada,” meaning “crossroads.” The design appears as a background motif on a small number of Ama-Ẹrọnmwọn (bronze relief plaques) and is associated with Olokun and the period of close contact between the Benin Kingdom and the Portuguese Empire during the reigns of Ọba Ọzọlua, Ọba Ẹsigie, and Ọba Orhogbua ( ). At the time of Ben-Amos’s research, the same symbol was drawn in chalk at the centre of Olokun shrine courtyards in Benin City. described the design more literally as a “circled cross” and suggested that the Ama-Eronmwon bearing this background motif may have been cast by a particular ‘master’ or member of the Igun-Ẹrọnmwọn.

More broadly, the cross, with its four points, references the number four, which has significance in Edo belief: the Edo week consists of four days, and each day is divided into four parts ( ). Other cross forms are treated as distinct motifs and are discussed separately under Uman-Ague (equal-armed cross).