i saw an alpha one time and it killed 3 of my very high level raptors and the first raptor i ever bred and my 2 dodos. It had about 3500 health and was impossible to kill without raptors and i was only on level 38 please stay far away.
Someone was asking about if they should try to kill an alpha raptor, No, No, No. Unless you have 2 Rex or Spino etc, they will kill all your creatures while you watch. My thoughts are to: 1. destroy all your structures, so you can start fresh. 2. Evacuate ALL your creatures. 3. find a safe, new island. 4. rebuild all of your stuff. Once an alpha raptor invaded my island and killed all my stuff except 6 things. Don't make my mistake.
If One is following you and you are not prepaired hide behind a larhe herbivore like a trike. The raptor will accidently hit it and they will fight to the death. Run while the battle is still hapening. Hope this helped. Up for noobs who have never seen a raptor