Animators Down Under is a take on the popular AU "Painted Plummet," but with seemingly more fitting roles. The AU has yet to have all roles taken, but here are roles for now. Note that most of these roles may change as long as this AU progresses.
Papyrus: James (TheOdds1Out)
Alphys: Jaiden (JaidenAnimations)
Mettaton: Rebbeca Parham (Let Me Explain Studios)