User blog comment:ArtDraw12/TD Theories: Who May Return in Potential Future Seasons?/@comment-26184706-20161018005902/@comment-11883116-20161018032207

Yeah, spud is unlikely unless Chef will make spuds again. Rock is very likely, basically only needs official confirmation to be counted as confirmed (although you can count him as such anyway). Lightning is unlikely, although storm usually happens in horror episodes, and there's always at least one.

Sugar will also come back if some episode will focus on food again. Sierra (name meaning = mountain) may also come back, I'll give her a maybe. Bridge is quite unlikely, but not impossible. Brick is very unlikely, unless there will be a brickhouse (or mentioned if someone will be called like that). Dawn is also very unlikely, most episodes take place in day and night time (rarely also during sunset).