Notes:

1000 hours of google image searching and ms paint pasting/resizing/cropping

• Genji – Raiden (Metal Gear Rising: Revengeance)
• McCree – Novakid (Starbound) (artwork by Bietol)
• Pharah – Blue Bird (Angry Birds)
• Reaper – "Not Important" (Hatred)
• Soldier 76 – generic counter-terrorist (Counter-Strike)
• Tracer – Judy Hopps (Zootopia)
• Bastion – R.O.B. (Nintendo Entertainment System Robotic Operating Buddy)
• Hanzo – Filthy Frank (Filthy Frank)
• Junkrat – "Hothead" (Dreamstime stock image)
• Mei – Nana (Ice Climbers)
• Torbjörn – Engineer, wearing the "Viking Braider" cosmetic item (Team Fortress 2)
• Widowmaker – Spider Woman controversial variant cover (Spiderman)
• D.Va – Kirby + Robobot Armor (Kirby: Planet Robobot)
• Reinhardt – Gypsy Danger (Pacific Rim)
• Roadhog – Peppa Pig (Peppa Pig)
• Winston – Donkey Kong (Expand Dong Donkey Kong 64)
• Zarya – Jigglypuff (Pokémon) (Don't ask why)
• Lúcio – Crazy Frog (Crazy Frog)
• Mercy – Eva Braun (Eva Braun, A.K.A. Hitler's wife for a day)
• Symmetra – Nicki Minaj (Nicki Minaj)
• Zenyatta – Mahatma Gandhi, with Rowlet orbiting around him (Mahatma Gandhi, Pokémon)