|This character is owned by|
While Marbles may appear to be nothing but a young, friendly girl, she has been often depicted as being vengeful, mainly towards her older brother Rex after he tries scaring her or pulling a prank on her. One of the most notable examples of this in one of the Easter-themed stories from the original Rex canon, where Rex plants scary traps in different areas where Marbles looks for eggs. At the end, Marbles ends up scaring Rex by putting a creepy face on his door.
Concept and creation
Much like a lot of the other Worst Chicken characters, Marbles was based off a Ganz Easter plush dog. One of, if not the first concept of her character, was a "damsel in distress" type character, where she would be rescued by Little Grey. It is unknown if at this point she was considered Rex's little sister, but she had always been at least once Rex was no longer considered a villainous character.
Marbles and Little Grey were always considered to be friends. At some points, it was hinted that they could have been dating, however this is no longer true as of the current canon, especially due to their large age gap. Little Grey and Marbles now share more of a sibling-type relationship.