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).

The Ubanu'hi (infinity symbol) is a kind of guilloche or interlaced strapwork motif that can be angular or rounded. It was used by Edo artists in the decoration of many Emwin Arhe (royal treasures) and is ubiquitous in Benin royal arts. Ubanu'hi is a shortened form of “uba no Ọba ya de agbon ke ehimwin yi”, which means “the rope with which the Ọba ties the heaven and earth together” (pers. comm. Chief John Igbineweka Inneh n’Igbesawman, 2022). Similarly, Paula Ben-Amos Girshick (in Plankensteiner 2007, pp. 339, 341) described this as “Ọba n’iri agbon”, or the “rope of the world” pattern.

According to Ọbabanmu Ineh (in Blackmun 1984, p. 51), the use of this motif indicates that objects were carved by members of the Igbesanmwan. However, the motif is found on all types of Emwin Arhe (royal treasures), not only those made of ivory or wood. On the flanges of the Ama (relief plaques) alone, Kathryn Gunsch (2018, pp. 75–77) identified three different versions of the Ubanu'hi and, through her analysis of over 850 plaques, found that these different Ubanu'hi forms align with other characteristics, such as dimensions, the prevalence of ornamental motifs, and stylistic qualities. Together, these provide evidence, she argues, of different production groups among the plaque makers .

Kate Ezra (1992, pp. 209, 264) went on to argue that the use of these motifs indicates that certain objects were used in a “royal context” and were associated with “royal patronage”.