Klaww Skip
Klaww Skip is a skip used in most speedrun categories to bypass the boss fight with Klaww and continue into Mountain Pass.
There are two known methods to perform the skip:
Lava Walk
By ledge grabbing the stone platform in the middle of the boss fight, Jak is able to clip into the lava without dying. Jak can then let go of the ledge and walk through the lava. If Jak performs any actions other than just walking, the lava will kill him. There is no known way to consistently perform this version of the skip, with most players citing a 1/4 or 1/5 chance of success.
Idle Deload
A slower but much more consistent method of skipping Klaww is by using an idle deload. If Jak visits Klaww, triggers the cutscene where Klaww smashes a rock pillar, then navigates to Boggy Swamp and performs and idle deload on a specific rock, Jak will end up respawning at the checkpoint behind Klaww. This puts Jak at the beginning of the Mountain Pass race.