Mrs. Johannsen (or Johansen or Johanssen) is a morbidly obese resident of Lawndale, usually shown in a mumu and struggling to breathe. In her first appearance she was said to have hypoglycemia and in her last, "Mart of Darkness", she mentioned having a seizure "a while back".
She first appeared in "Cafe Disaffecto", when Daria and Jane had to sell candy bars door-to-door. Johannsen attempted to buy the whole lot, saying it'd be okay with his doctor as long as he never finds out, suggesting that she is not specially interested on following strictly the treatment for her hypoglycemia. In the midst of the attempted steal, Mrs. Johannsen suffered a hypoglycemic attack (having just run up the stairs to get there) and fainted; Jane's response to this possible death was to take a photo. When Johannsen got up, the girls refused to sell even at $5.00 a bar and so she complained to the school. Angela Li tried to figure out an excuse so they could kill a woman for money ("How do you know it wasn't for her family?").
In "That Was Then, This Is Dumb", she was a shopper at the flea mart.
In "Psycho Therapy", she was a psychiatric patient at Quiet Ivy, muttering to Dr. Millepieds that she uses food for comfort "at least a chocolate bar never told me I was an accident", which suggest her hypoglycemia was probably the result of a traumatic (or at least hard) childhood.
In her final appearance, "Mart of Darkness", she fought a running battle with Mr. DeMartino for free snack samples at Pay Day. The two of them got banned from the free samples table for their gluttony and conflicting, causing her to threaten DeMartino with vengeance.
- Rarely for the minor characters, Johannsen got her own Alter Ego.
- Going up the stairs quickly shouldn't really cause this big a hypoglycemic shock, unless Johanssen has also been skipping meals - see what your fat shaming did, MTV?
- Not feeding her candy was the correct choice, though not for the reason Daria and Jane seem to think (they seem to think she has hyperglycemia, too-high blood sugar): candy bars and chocolate contain fat which slows down the release of glucose.
In "It Slipped Through My Hands, Like a Shadow, Like a Dream", an alternate universe version of Quinn is the one who visits her selling candy bars and as a result, Mrs. Johannsen ends up in a coma. The fanfic says she was a Type 2 diabetic and the medication made her hypoglycemic (this is a real-world effect of some diabetic medication), and "a sufficiently large amount of sugar in her bloodstream would overwhelm the medication and worsen her condition".