Spinebiter has an ability that is seen from time to time on green creatures. This ability allows the controller of an attacking Spinebiter to have it deal its combat damage to the defending player even if it is blocked. (Because of the way it mimics trample, this ability is sometimes referred to as ‘super trample.’) There are two important things to note about this ability. The first is that this is an all or nothing choice. When you assign combat damage from an attacking Spinebiter you can either choose to have it deal its combat damage to creatures blocking it or to the defending player. This ability does not allow you to split it up.
The other thing to be aware of is that if this ability is taken advantage of the Spinebiter will still receive combat damage from the creatures that are blocking it.