It could be that the friend broke a promise or didn't support the animal when it needed help. That might make the animal angry.
The cartoon animal might be pulling its ears in frustration because it lost something important or didn't get what it wanted. It could also be feeling misunderstood or left out.
Mad cartoon animal eyes typically stand out with their uniqueness. They might have a distorted size, like being overly large or small. The iris and pupil could be in unconventional colors or patterns. Also, the way they move or blink could be very exaggerated and funny.
The cartoon dog could be mad because it lost a game or its toys were taken away. Sometimes, it might just be having a bad day, like we do!
The cartoon cat could be mad because it faced some kind of threat or had a bad encounter. Or perhaps it's just having a bad day!
Maybe she had a bad day or someone did something mean to her.
Maybe she didn't get what she wanted, or someone upset her.
Maybe she didn't get what she wanted or something bad happened to her.
Maybe he didn't get what he wanted or something bad happened to him.
Maybe it didn't get its favorite treat or someone scared it.
The cartoon boy might be mad because he was misunderstood by his friends or didn't do well on a test. Sometimes, even small things can set someone off and make them angry.