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).

Representations of figures, often the Ọba, with an Ukhurhẹ (Ancestral Staff) in their right hand recur in a number of Emwin Arre (royal treasures), particularly those carved in wood as Agba (royal stools), cast in brass as part of Osogan (Osun staffs) and Ikẹgobọ (altars to the hand), and carved in ivory as Aken'ni Elao (carved tusks).

Ukhurhẹ are rattle staffs, usually made from wood, although brass examples are believed to have been owned by the Ọba. Ukhurhẹ were, and continue to be, commissioned when the paternal head of a family passes away as a way of commemorating them ( ). Following a ceremony in which they are installed on the family’s ancestral altar, Ukhurhẹ are typically lined up against the back of the altar and are used to communicate with ancestors and the spirit world. When depicted on the Emwin Arhe, Ukhurhẹ are usually held in the right hand of the Ọba, while an Ughavan (celts) is carried in his left hand.

The Ukpan obọ eva (coral-bead crossed baldrics) were worn as part of the ehaingbehia, the full ceremonial regalia, by only high-ranking members of the palace, including the Ọba himself, the Iy’Ọba, the Edaiken, and the Ezọmọ (Ben-Amos 1999, pp. 68, 141; Osadolor in Plankensteiner 2007, cat. no. 70, pp. 322–323).

This motif of an Ọba with legs represented as two mudfish is often interpreted as Ọba Ohẹn, who reigned c. 1334–1370. According to oral traditions, Ohẹn suffered from paralysis of the legs and unsuccessfully attempted to conceal his condition from the chiefs and members of the royal court. The Iyasẹ Emuze eventually hid in the Ọba’s chambers to discover his secret ( ). When Ohẹn discovered this, he ordered the Iyasẹ to be executed. However, the people learned of the order and turned against the Ọba. According to the tradition, they plotted to kill him ritually by digging a hole beneath his throne and stoning him with Orhue (white kaolin chalk) when he fell into it ( ; ).

Not all representations of an Ọba with mudfish legs, however, are understood to refer to Ohẹn. Variations in the objects and animals carried by the figure are thought to indicate different meanings ( ; ). Members of the Igbesamwan and Igun-Ẹrọnmwọn have emphasised the significance of these accompanying motifs (Blackmun 1984, pp.249–255). When the mudfish-legged Ọba is shown holding aquatic creatures such as crocodiles, for example, the image has been interpreted as a “cosmological image” representing the correspondence between the two monarchs: the Ọba of Benin, ruler of the land, and Olokun, ruler of the waters ( ). By contrast, representations in which the Ọba holds swords or staffs have been interpreted specifically as depictions of Ọba Ohẹn.

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”.