Forum:Spear Cretin

Ok, so does Spear Cretins effect activate as soon as he is flipped? In other words if your opponent attacks Spear Cretin while he is in face down defense position, with an attack greater that Spear Cretin's defense, the flip effect is activated and Spear Cretin is immediately destroyed. Does this mean that you can summon the monster due to his effect this turn? or does the flip effect have to be activated BEFORE the battle phase in which he is killed?

Thanks,

Squagem