In the episode "The Snarffles with the Sniffles" (also known as simply "The Snarffles with sniffles" or some variant), The titular canine "Snarffles" gets swooped up by a hawk at the end, it is implied that he meets an untimely end.
In the episode "Konfusion" there is a lot of offscreen vomiting, but vomit itself is shown.
At the end of the episode pop goes the bubble, the characters Kin, Kon, & Laney, all vomit offscreen.
In the episode "Hologroj", the character Kon is beaten up by holograms, in the shot afterwards, you can see he is missing teeth
Also in the episode "Zoohouse Rock", the character Kin mentions how he had lost 3 teeth due to mixing candy and soda, he shows the gaps (healed over so there's no blood, but still)
There is a several second scene where the main character is choking in the episode "Line of Cred", it's played for laughs and the main character is fine afterwards
In the episode "Myme Disease", a ghost is briefly present in a scene
The character "Trina" is turned into a spirit in the episode "Soulin' down the road".
In the episode "Group Hug" the band is kidnapped by the characters Kate & Allie. It is a large plot point so if this bothers you i would recommend you skip the episode.
It is a running gag that the character Laney is called "Dude, Bro, Man" etc. and that she is a boy.
There is also a brief scene where the character Lenny is lumped in with his band (who are girls) by the character Corey.
Spiders are briefly shown in a scene in Girlfest, as the characters Kin & Kon think up ways to scare the characters Kate & Allie. they are cartoony in appearance and only show up briefly.
In the episode "The Snarffles with the Sniffles" (also known as simply "The Snarffles with sniffles" or some variant), By the beginning, a rat gets swooped up by a hawk at the end, it implied that he meets an untimely end.