The World Serpent's Gifts
Why honor the Serpent at all? Some claim that the Snake is an enemy of mankind, but those of us who work with the World Serpent have seen no evidence of this. In fact, many of us have learned important things from the Serpent, who seems to have a lot to teach about liminality, being neither one thing nor the other but both. It also teaches about the ley lines, the energy lines in the Earth, and under the sea, and how to follow and use them. Some people have learned something vaguely like Kundalini from the Serpent as well. It is a mysterious spirit, and may have more to teach that we don't know.
The Serpent does not seem to mind its destiny of becoming the living protective barrier around the world of humanity. As such, the Serpent can be called upon to protect a space, or a person. It can teach them boundaries while it protects them. To call upon the Serpent, put its rune - Ior - on the door of the space to be protected, or on the body of the person (with magic marker). If you know someone who needs better boundaries, you can ask the Serpent to help them.
The World Serpent was created from the magic of the Iron Wood acting on the combined bloodlines of Loki and Angrboda, two of the most powerful Jotnar the Iron Wood itself ever brought forth. Of all the Jotnar that I've dealt with, the Big Snake is the one that I think is most easy to misunderstand. It is an incredibly alien creature. Touching its nature is very strange. It is hermaphroditic - not terribly unusual for the Iron Wood - although it tends to "feel" to the person contacting it like whatever their gender is. It doesn't speak in words, or any kind of a language that we would consider a language, but it does speak, somehow. I can't explain that - it boggles my mind to try - but the one time when I shared a body with the Snake (which seems to have no name; as it is unique, it doesn't feel like it needs one, it is simply "I") it felt as though all the verbal parts of my brain were being shoved aside and disconnected. It took an hour before I could properly speak, after that.
As for an offering for Jormundgand: The Great Serpent actually has its own charity! It's Midgard Serpents Reptile Rescue, and if you want to make the Big Snake happy, you can contribute to its favorite charity.