I've heard it said that they rage after 10 seconds, then go back to yellow after another 10 seconds but I haven't had the chance to time it myself. It is also not an uncommon sight to see two Fleshpounds raging-rushing you from out of nowhere for no reason. Unlike KF, this big guy is a lot harder to hear so there is a chance that he may sneak up on you. Very big and very angry, his charge is both fearsome and extremely dangerous. Keep shooting/Pulverizing and make sure your area is clear of other trash Zeds. Back up, wait to parry, then stagger again because it has a cooldown. The Pulverizer heavy attack staggers the Scrake. This takes very good timing and I recommend body armor when you try it.
A Berserker can play parry-hit-parry with one reasonably well if they're armed with the Pulverizer.In the higher difficulties, a Scrake can take you down from 100% health to dead in 1-2 hits if you're not wearing armor. Where before it was possible to Fire Axe stun him or make an easy headshot with the crossbow in KF, Early Access players don't have nearly the same kind of firepower. Seriously dangerous once he closes in, so don't let him corner you. You'll know when this one is inbound by the sound.
