Can a Girallon who is climbing on a cliff-face charge at a PC who is also on the cliff-face, or perhaps looking over the end of the cliff?
I would assume doing so is an "accelerated climb."
Climb
A creature with a climb speed has a +8 racial bonus on all Climb checks. The creature must make a Climb check to climb any wall or slope with a DC of more than 0, but it always can choose to take 10 even if rushed or threatened while climbing. The creature climbs at the given speed while climbing. If it chooses an accelerated climb it moves at double the given climb speed (or its base land speed, whichever is lower) and makes a single Climb check at a -5 penalty. Creatures cannot run while climbing. A creature retains its Dexterity bonus to Armor Class (if any) while climbing, and opponents get no special bonus on their attacks against a climbing creature.
