Big Sam and Small Sam are parent and child robots Dr. Go created to defeat Kuro. They are capable of flight and can eject powerful acid liquid that can "dissolve anything". Upon activation, Dr. Go's cluelessly installed motherhood into Big Sam's programming causing "her" to run amok after Small Sam ran off. In a panic fit, Big Sam's self-destruct mechanism was mistakenly activated, but she was saved thanks to Mi's efforts. They have frequently appeared as regular side characters since. In both the game and anime, the Devil possessed them turning the robots into Devil Big Sam, Devil Small Sam.
- The naming for Small Sam was just an intentional gag of "Big Sam, Small Sam".
- Their names were just used only once upon introduction until nicknamed down to "Ohsamu, Kosamu(オーサム、コサム)"