Who is Mordgud?
What we know from myth, history, and inspiration
Mordgud is the "maiden etin"
who guards the main gate of Helheim. "Maiden etin", translated into
Jotun terms, seems to refer to an unmarried female warrior, more the Amazon
than the blushing human maid. It is akin to understanding the different
Hellenic words for an unmarried woman; kore implied innocence and
fragility while pallas implied something fiercer and more warriorlike.
However, while Mordgud is a tall, muscular etin-woman who generally appears in
shiny black armor, she is more than just a thug at the door.
Mordgud has also appeared as a skeletal figure (one of her illusions) or a forbidding dark shape with a loud voice. Her tower, built of the black shiny stone that seems to be so common in Helheim and Muspellheim, stands by the Gjallarbru bridge, on the far side; if you make it over the bridge, you then have to deal with her. Don't try to slip past her; she has had millennia of experience in discerning the dead from the living, and you won't be able to fool her for a second. She will stop you, and you must state your business. If you have no specific appointment, she might turn you away. At that point, you'd best go home and try to get through to Hela, her boss, and beg for an appointment. If you get no answer, you're probably out of luck and Her Ladyship doesn't want you visiting.
If Mordgud does let you by, she may demand that you leave something behind as a token of your good behavior. If she asks for this, you should immediately give her the most valuable thing that you are carrying, unless it is something to be delivered to Helheim. She is honorable and will give it back when you return past her watch, unless you misbehave yourself and incur Hela's wrath. Other reports say that she requires people to recite their ancestry, or at least their families, so be ready in case this comes up. If you don't know your ancestors, say so; don't make them up.
Some reports claim that Mordgud extracts a toll of blood from living people wishing to enter Helheim. At any rate, it is good common knowledge that one ought to give a token of blood whenever dealing with the deities of death - some won't even look at you unless blood is involved - and it's not surprising that Mordgud might demand some. Have a lancet on you just in case. Understand that leaving your blood with her is more than just an offering; it's leaving a bit of your energy behind so that you can be controlled should you act up.
"I've always experenced Mordgud as a Goddess who brings the awareness that wisdom need not always be beautiful to be true." -Galina Krasskova
Although her job is very much like Heimdall's - she does seem to be his "opposite number"- she is more than just a security guard. Mordgud has seen as great deal of death, and has shepherded many people from the realm of the living to the realm of the Dead, and she has deep knowledge and wisdom of such transitions. She is a psychopomp in her own right, and can be called on by those who feel stuck in their own dead places. She may not lead you out, if the time isn't right, but she might point out the way for you.
Artwork by Tansy Appleby.