Dota 2 rank icon mods
The medal beside a name. Local only, so it changes nothing about your actual rank.
The D2PFX catalog has 10 mods in this category. Each changes what you see on your own screen; everyone else sees their own game.
Battle Icons
Immortal Ranks
Normis Rank Icons
Umbrella Medals
Slates of the Damned
Azur Lane Medals
Bear Medals
Void Medals
Flaming Medals
Imperial Medals
Installing any of these
Open Dota 2 Mod Manager, find the hero, press Install. The app puts the file in a free pak slot in the folder your game mounts, tells you when two mods carry the same file, and puts everything back after a Dota patch. The full guide, or the manual route if you would rather do it yourself.