What capabilities does a Vampire have inside an anti-magic field

Question

In a campaign I've been playing we recently stumbled upon a town (population of a couple of thousand) that was hidden via a large scale illusion spell, and shielded from the outside world, via a large Antimagic Field.

We were told by some of the populace that a friendly Vampire lived in town.

Which got me thinking, what are the capabilities of a Vampire living within an Antimagic Field?

Some are obvious, it cannot use its Children of the Night or Charm actions, as they are explicitly stated as magic.

But can it use Shapechanger or Spider Climb? Are the Vampire Weaknesses applicable in an Antimagic Field? Does it regenerate in an Antimagic Field?

Are these pretty much all up to the DM?

Answer 1

Only Charm and Children of the Night are magical.

In DnD 5e, according to the Sage Advice Compendium, a creature's abilities only count as magical if they meet one of the following criteria:

• It is an ability of a magic item
• It is a spell, or specifies that it creates the effects of a spell
• It makes a spell attack
• It is fueled by the use of spell slots
• Its description says that it is magical

So, by checking over each of a Vampire's abilities, we can evaluate whether or not they are magical. By doing this, we can see that none of the vampire's abilities are the result of magic items, so none of them meet criteria 1; it has no spellcasting abilities, spell slots, spell attacks, or abilities that replicate spells, so none of its abilities meet criteria 2 through 4. That just leaves criteria 5, and we can see that only two of its abilities are described as magical: Charm and Children of the Night.

As a result, those two abilities are the only abilities that are considered magical, and the only two abilities that the vampire would lose while in an Antimagic Field.