Heres how I imagine him greeting someone: "*SCREEEEE* Oh hey! Sorry, that was my arm detaching. Hi! I'm Bopper! Try not to touch me, I'm currently at 98% inflation and I'm feeling fragile today."
That in the project is just him every Monday and that thing sticking out him is just his balloon string don't ask him about it though and for real I feel he would sound Slightly Squeaky & Rubber-Like or Helium High Pitched voice
