Gregg is somewhat taller than K.O. but shorter than Enid, and they have a white beak, feathers, and legs. Gregg's attire is magenta shorts with matching shoes and a teal sleeveless shirt. As seen in "Second First Date", Gregg is seen wearing a light teal eggshell and teal shoes.
Gregg has low self-esteem and gave up on any dreams of being a true hero. They loiter around the plaza with a group of delinquents. Gregg is kind of a hanger-on, and they mostly just squawk in support of whatever Red Action or Drupe say. They have a serious temptation for seeds and will do anything to get them.
Gregg has no known special attacks. They just peck enemies when threatened.
- "You're Everybody's Sidekick"
- "You're Level 100!" (cameo)
- "You Have to Care"
- "Plaza Prom"
- "T.K.O." (cameo)
- "Second First Date" (cameo)
- "The Power Is Yours!" (cameo)
- "KO's Video Channel" (comment on video)
- "Plazalympics" (cameo)
- "We Got Hacked"
- "Back in Red Action" (social media post)
- They are a surprisingly good cook of many international dishes.
- In "Second First Date", they are seen having ice cream with Drupe when they were kids, revealing that the two knew each other since childhood.
- Gregg and Colewort are seen having a picnic together in "T.K.O.".
- Gregg and Potato are seen having ice cream together in "The Power Is Yours!", and going shopping together in "We Got Hacked".
- Gregg's reference sheet on the official OK K.O.! Tumblr avoided using any pronouns when describing Gregg.