Just another one from the scarab:
Defense is X, where X is the number of scarabs the owner controls and X is applied at the end of the owner's turn. Just to name the known facts.
But if a scarab devours a creature, it gets +1/+1 during the turn the devour takes place (because it's not a counter / mark / whatever stacking on the creature, like poison). So at the end of turn, when X is applied again according to the number of scarabs, the scarab must lose the one point of defense.
Regards, Reefa.