"I was told I make intelligent comics, and then I made a comic about a horse that pooped."
— Kate Beaton
Hark! A Vagrant is a largely history-based Webcomic by Kate Beaton best known for its historical comics, which are one-shots of varying length focusing on historical events or figures. There are occasionally other kinds of comics, including comics in which Beaton visits her younger self, a few comics about a pony called "Fat Pony", and a story about a sailor who meets a mermaid. There is little continuity and each comic is a standalone strip. Also, rather than use Alt Text, Beaton usually accompanies each comic with a short paragraph.
Marat spends all his time in the tub because he really likes baths.
"Sometimes? I pretend to be Neptune."
Also, her Nancy Drew comics. Essentially, she takes the covers to old books in the series and comes up with... alternate explanations for the scenes shown. Other characters are often shown worrying about Nancy's mental health.
Black Comedy: Historical events and personages are depicted in a comedic manner, even the darker, more terrifying ones. To be fair, Kate Beaton does it well.
Real Dreams Are Weirder: This strip. Calpurnia dreams that Caesar is going to be killed on the Ides of March. Caesar dreams about robes made of hot dogs.
Protagonist: Doctor, there's a woman in the wallpaper. Doctor: That woman has a feminist agenda. Tell her to get in the wallpaper that's in the kitchen.
In another strip, a man finds out the book he's reading was written by a woman. He then drops the book and tells a random woman "Shame on you!"
Viewers Are Geniuses: To an extent. Knowledge of European and North American history certainly helps, as the comic isn't going to explain the characters and events to you, but most of the time the comics are funny even if you don't know the history. (And at any rate, there's always The Other Wiki if you need a refresher... Hell, it's a webcomic, so you must be close to a search engine, right?)
Your Mom: The "Your Wife" variation — Tycho's rude response to Kepler suggesting the possibility that the sun might orbit around the earth as opposed to him believing in the opposite.