On 8/4/21 the NPC update introduced a brand new NPC testing system. It allows you to spawn a test dummy named Marvin. Marvin will follow you around the map & hangout with you by your cauldron.
You can give Marvin potions & make him drink them to experience its effects. This is an easy way to test potions instead of having to test them on yourself or wait for other people to try them.
When you use a potion on Marvin he will also say a unique voice line depending on what you give him or what’s happening to him.
The voices are mostly likely recorded by the developers themselves. Is it Jandel or Foryxe?
– Fire Potion: “Oh I’m burning, I’m burning!”
– Tiny Potion: he will say “I don’t understand what’s happening to me!”
– Giant Potion: “Ooh yeah this is good”
– Frozen Egg: “Ooouughh”