Behind the Scenes #23 (Patreon)

Right at the beginning of the story, staying faithful to the Diaper Quest tradition, there are a lot of references to videogames and movies and most of them are present in the arena scene. 

In any particular order here's the list from that specific chapter:

Page 8:Skyrim-like character. 

Page 9: A giant from Shingeki no kyoujin, Kimahri and Wakka from FFX, Etna from Disgaea, Link from Legend of Zelda, a Mekemeke from Guru Guru, Nino from Fire Emblem, a Beholder from D&D, Goku SSJ and Kaioshin from Dragon Ball Z, Steve from Minecraft, a wizard from Magika, Ed and AL from FMA, 

Page 10: Aku Au from Crash Bandicoot, Zenyatta from Overwatch, Aladdin's flying carpet, a void minion from Warcraft. 

Page 28: Nike and Kukuri from GuruGuru and Gragas from LoL. The arena itself is a reference to both Oblivion's arena and DragonBall's.