It's been a while since we talked Phineas & Ferb, so I knew I needed to check in to see if there were any new theories being concocted in that backyard. It turns out, there totally IS! Today Theories, we are talking about the killer plant from SPAC! In the 'Phineas and Ferb the Movie: Candace Against the Universe' we come up against an alien species that needs something from earth. Theorists, that is just the set up to a KILLER theory!