after you outran the twisted version of poppy and reached floor 5, you extract some machines that contain ichor while the other toons do the same...while you were extracting the machine, something has grabbed you from behind, making you stumble backwards. yes. its goob who was dragging you, before he could hit you, you managed to get out of his grip and started running somewhere while hes chasing you. but thankfully someone is distracting him so he wont chase you...for now...

anyways, you just need to be careful because if youre off-guard, youre dead. he can literally grab behind you and try to kill you.