One possibility could be a red chameleon. They often have distinctive eyes that could be depicted in a cartoonish way.
It could be a vampire character. Vampires in cartoons often have red eyes to show their supernatural nature.
Maybe it's a sci-fi phone cartoon where a character has red eyes due to some technological experiment gone wrong. Or it could be a fantasy one where a magical creature has red eyes and is holding a phone.
It could be a fantasy creature like an elf or a goblin with unique features like red eyes.
It could be a cartoon of a mysterious vampire with red and black eyes to add to the spooky effect.
It could be a cartoon of a fantasy creature with magical powers and distinctive red high eyes.
Well, some horror or fantasy cartoons might have characters with evil red eyes. Like in certain vampire or demon-themed ones.
Maybe a cartoon of a chameleon with orange skin could fit. They change color and having orange for a moment isn't impossible.
It could be a fantasy cartoon where the red cat with green eyes has magical powers.
It could be a fantasy cartoon character, maybe part of a magical adventure story.
Maybe it could be from a fantasy or horror-themed cartoon. Such a character might be found in shows that focus on supernatural creatures and their adventures.