Oz can be found in a shack inside his cave. The cave entrance is covered in bushes behind the largest tree located on the map. You can walk through these bushes even though they look solid.
Oz is an NPC that can be interacted with. When interacted with he gives dialog about the world.
You can also hand in cyclops eyes to him to earn rewards from Mr. Rich such as the Robux ingredient & gems for the gem shop.
He is one of the main NPCs in the storyline of Wacky Wizards.
Oz was added to the game around June 23rd, 2021 as one of the first updates to ever be introduced in Wacky Wizards.