weak spot trait

[vercinjetorix]

The weak spot trait says that

The creature has a vulnerable or exposed area, which it attempts to protect at all costs. A character attempting
to strike this area incurs a -12 penalty on his attack test: if he succeeds, the creature’s Vitality score is halved for this attack.

But what if the extra has stats just like the hero characters. How does it work, since a character does not have a vitality score?

[Corone]

Technically, such a creature would have some of the more complicated traits for full characters.
But I'd go with half its Life Points if you hit.
I'd also maybe make it a killing blow if it is down to a quarter of its health.

[vercinjetorix]

Thank you