I was scared of certain types of CGI as a kid and remember being scared of the Jimmy Neutron VHS tape at my grandma's house because of the animation style but I was probably really young. I think Animalia similarly unnerved me but I can't remember being scared of it. I also remember watching Simpsons as a youngish kid because my parents loved it and being scared of some by the scenes that involved blood. I think certain Ichy and Scratchy segments and the episode where Homer cut off his finger did it but I can't completely remember.
Motherboard from Cyberchase also scared me but the scene where Hacker takes over Motherboard terrified me when I was 3-5. Imagine this as a preschooler who's already slightly scared of CGI.
For some reason when I was little, I was terrified of the character on Sesame Street called Horatio the elephant. Probably because of the character’s shrill voice.
None of the other characters bothered me except for that.