Pest has a blocky build, mainly resembling a 2011 Roblox Guest. His face texture features a devious grin with two sharp red eyes and red accent lines below and above the eyes, giving the impression of slight eye bags and brow creases. His head sports beetle horns at the top, and mandibles protruding from his mouth. His teeth are sharp and white, as seen when grinning.
All of his body parts are black with his head having a black shadow on top. On the front of his upper body is the word "Regret" in Japanese hiragana (こうかいする, Kō kai suru), and on the back of his torso are the words "Do you regret your decision?" also in Japanese. (自分の決断を復悔していますか？) The numbers "1314" in red are vertically placed on his left arm. He also sports a modified version of the Roblox "R" Baseball Cap, with the R slightly rotated to the right and replaced with a P instead.
Personality-wise, Pest is standoffish from the other NPCs. He is a loner and doesn't wish to make friends, denying the fact whenever an NPC calls him one, often making them depressed. He is easily annoyed, straightforward, and will often steal items and lie about it when asked if he knows where they've gone. Pest tends to insult other NPCs in Japanese so they cannot understand what he is saying. Despite this, he may have a somewhat softer side to his personality, such as his interactions to DrRETRO or him apologizing for snapping at Spud.

So.... this character has a lot to do with  the japanese language, so bonus points if you can speak japanese! :) 

( i see him as like a demonic character with a japanese accent, sort of like genji from overwatch with a demon hint to it, but do whatever!)  you can also just make  him sound like the way he laughs but with a voice 
https://regretevator.fandom.com/wiki/Pest Wiki for him!