Prey Upon can creature that loses the fight be regenerated?

[Inside]

if my creature dies from a fight with Prey Upon can it be regenerated?

[Jake1991]

Yes, but you would have to regenerate it before Prey Upon resolves.

[Inside]

what do you mean

i am using Heal the Scars

i dont even know what creature he will attack before he casts the prey upon

[Kenji]

You won't know which creature is going to be affected before Prey Upon is cast -- that's obvious.

However, Prey Upon has two distinct targets when cast: "target creature you control" and "target creature you don't control". So, when your opponent casts Prey Upon, you would respond with Heal the Scars to regenerate the creature he targeted. Prey Upon, like every other spell in existence, doesn't resolve until all players pass priority without adding anything to the stack. So, you certainly have the opportunity to use Heal the Scars here.

Remember, a regeneration "shield" must be put up before the creature would be destroyed. If you wait for Prey Upon to completely resolve, your creature will be in the graveyard before you're able to cast Heal the Scars.

Also, a note on the fight mechanic -- this is not considered as an attack, doesn't count toward combat damage, etc.