A teen is shown occasionally launching items towards the wall or his bed out of rage.
In one episode, a woman shoots her boyfriend dead with a shotgun (we don't see any blood or the man suffering the wounds). This is meant to be darkly comedic.
In one episode that deals about zombies, the zombies are seen to have rotten skin and bloody mouths, though it all looks very fake. The incredibility of the blood and makeup is meant for comedic effect.
In one episode, a man vomits white liquid. The substance is censored.
In one episode, a man slaps another man after the latter spoiled his favorite TV Show.
Russel (the teen seen in the talking heads of the videos) occasionally makes violent and graphic descriptions. It's all meant for comedic effect.
In one episode that talks about being a father, in a darkly comedic scenario, after the father grows impatient with his son's behavior, he pulls out a pistol and shoots him dead off-screen.
A few occasional slaps and punches.
There are rare scenes of violence, but there are some mentions of bodily functions in a humorous manner.
In a Halloween-themed episode, a man dressed as Jason Voorhees comically slices Russel into slices, which causes the latter to break apart in pieces. It looks very fake and meant for comedic effect.
A few comedically intense arguments.
In one episode, after a couple enters an intense argument, one of the lovers strikes their partner with a metal rod and then kicks them in the face. The aftermath shows the twitching body with a little bit of blood (the blood is ketchup). This is meant to be darkly humorous.
The violence is usually (and only) limited to fist fights and comedic accidents that involve non-graphic injury.
While violence does occur, it is not the focus of the show.
In one episode, a woman vomits into a trash can in front of her co-workers, causing several of THEM to vomit (with some of them partially or completely missing their trash cans). And the camera close-ups on some of them.
Violence in the show is mostly reserved for comedic moments. But in one particular episode, 'Animals Feel as Well' (which is infamous for being the most serious and emotional episode of the show), there are very graphic descriptions said by Russel in a very emotional manner. This can upset and disturb viewers.
When blood is depicted, it's usually depicted with ketchup, meant to look fake for comedic effect.