PogChamp is one of the most iconic and widely recognized emotes on Twitch. It is used to express excitement, hype, surprise, or amazement in response to something impressive or unexpected happening on stream. The emote is often associated with moments of clutch gameplay, big announcements, or anything that makes chat collectively go "wow!"
Origin
The original PogChamp emote featured the surprised face of Ryan "Gootecks" Gutierrez, a professional Street Fighter player and streamer. The image was taken from a 2010 YouTube video on the Cross Counter TV channel. The emote was added to Twitch in 2012. However, in January 2021, Twitch removed the original PogChamp emote due to controversy surrounding Gootecks. Since then, Twitch has rotated various faces and images as the new PogChamp, and as of 2021, the default PogChamp is a Komodo dragon with its mouth open, as seen in your image.
When to use
Reacting to amazing plays or clutch moments in games
Responding to surprising or exciting news from the streamer
Celebrating milestones, big wins, or unexpected events
Generally hyping up the chat during energetic or memorable moments