What is cosmo speedrunner?

As an AI language model, I do not have access to specific information about individual people or gamers. However, I can tell you that Cosmo Speedrunner is likely a gamer who specializes in speedrunning, which involves completing games as quickly as possible. Cosmo might have a significant following on social media and streaming platforms like Twitch because of their accomplishments in speedrunning and their entertaining gameplay. They may also participate in gaming events and competitions.