I think it's only vegetarian. It looks like it has egg whites according to the Fluff FAQ page:
Is Fluff gluten free?
Yes; it is also Kosher. [top]
[...]
What is Fluff made from?
Corn syrup, sugar syrup, vanilla flavor, and egg white. There are no artificial preservatives, stabilizers, emulsifiers, or colorings in Marshmallow Fluff.
no subject
Is Fluff gluten free?
Yes; it is also Kosher.
[top]
[...]
What is Fluff made from?
Corn syrup, sugar syrup, vanilla flavor, and egg white. There are no artificial preservatives, stabilizers, emulsifiers, or colorings in Marshmallow Fluff.
no subject