Hunter and warlock pets are almost invulnerable in dreaenor chromy time.

[Lipro]

I was leveling a pack of alts in draenor and noticed that at lvl 45 the hunter's pet almost stopped taking damage. I tested it on a pack of nock karosh and it lasted almost 10 seconds, while 1 wolf oneshoots me, and pet can easy tanking gorgrond world boss.
So I stopped the exp gaining at capital and with this hunter tracked down and killed almost all the mountable rares of Draenor, these guys didn’t give me a chance before.
Oh and i just tested it on warlock and it works at least at 45 and 46 lvl voidwalker.

[advanta]

I was leveling a pack of alts in draenor and noticed that at lvl 45 the hunter's pet almost stopped taking damage. I tested it on a pack of nock karosh and it lasted almost 10 seconds, while 1 wolf oneshoots me, and pet can easy tanking gorgrond world boss.
So I stopped the exp gaining at capital and with this hunter tracked down and killed almost all the mountable rares of Draenor, these guys didn’t give me a chance before.
Oh and i just tested it on warlock and it works at least at 45 and 46 lvl voidwalker.

This happened to me also and has been reported elsewhere, but the exact trigger isn't known currently. It is something more than switching to timewalk mode. Btw It isn't limited to draenor tw.