"Muggen sopp i skogen" are moldy mushrooms in the wild.
The Henrik hates the "muggen sopp i skogen", and whenever he sees one while he's on the tur in the skogen, he goes into a temper tantrum and gets a heart attack afterwards, nobody knows why.
Person: Hey Henrik, i think i see a muggen sopp over there, in the skogen.
Henrik: LASJHKØGYAJHKSLØDFYUGASBHJKFGHAVJSDKPDH NEIIIIIII JEG SKAL BANKE DEG ASKODJIUHASJID, FUCK MUGGEN SOPP I SKOGEN!!
Swogen, or sometimes swogenleg, is the Norwegian word for a limp, but it can also refer to a clubfoot. For whatever reason, the word is now being used in Montgomery County, MD to describe guys who drop their friends for new girlfriends. Apparently, swogen is an insult in Norway, where people who appear weak are looked down upon, and it now refers to the person's character. There is a large Norway population in Montgomery County because of the embassy in Washington D.C. which, presumably, is why the word is so commonly used. Now, the forgotten friends are known as swogenhaters.
Person 1: Dude, where is Person 3?
Person 2: He's with his girlfriend tonight, dude.
Person 1: For real? What a swogen?!