The Green Tentacle skip

To skip the Green Tentacle, enter the corridor where the Green Tentacle is waiting for you. Get close to it (but not too close) and then switch to a different character. Switch back to the character who's next to the Green Tentacle, and click on the left to move past it. Note that your character will try to go back at some point, so keep clicking for a while. Once you've heard a sound and your character has said "Oomph!" or similar, you can stop clicking. You'll notice that, most of the time, this results in your character briefly stopping before continuing to walk, but sometimes your character will continue walking without stopping. Currently I don't know what causes this behavior to be different sometimes.