The image on Grogu's rondel was that of a mudhorn.
A rondel functioned as a protective, circular piece of metal, integrated into armor designs. The Armorer crafted a rondel specifically for the foundling Grogu, utilizing beskar remnants contributed by fellow Mandalorians to aid foundlings. She attached it to Grogu's armor herself, stating its purpose was to safeguard him as he matured into his role as a Mandalorian.
The rondel bore the emblem representing Clan Mudhorn. During the events of the Conflict on Mandalore, Grogu's rondel proved effective in protecting him during his confrontation with the Imperial Praetorian Guards, when a substantial metal beam collapsed onto Grogu.