Anything that exists can be a concrete existence capable of turning into an existential object. Every single thing: sand, a rat, a plate, a bud, a sausage, a baby being born. And every single activity: eating, walking, giving birth, dying. While anything and everything can become an existential object, it doesn't happen quite often. Probably, because the meaning contained in the being is not very clear and is rarely obvious. And we are not attentive enough.