Messaging including custom characters with embedded content

Embodiments described herein enable messaging using custom characters (e.g., custom emoji) that are not part of a Unicode Standard, as well as associating such custom characters with embedded content. The embedded content can be, for example, a quick response (QR) code, a coupon, an advertisement, a map, a static image, a moving image, a video, audio, or combinations thereof. A client device receives message data including a unique custom character reference. The client device obtains (e.g., from a remote server) image data and embedded data for the custom character associated with the unique custom character reference. The client device uses the image data to display the custom character associated with the unique custom character reference. The client device displays embedded content associated with the custom character, in response to accepting an indication that a user of the client device has selected the displayed custom character.