Of course, Goat Mom and Wolf (Children's) Mom have to be included. And you can't have Holly Joestar and Lisa Lisa without Jolyne's mom! She's the Over Heaven tier!
I think it's because this portrays mothers of particularly famous characters; both Gohan and Trunks are very important to the fandom; and although I love Marron, she's not that much of famous...
But Big Mom is there. She's a mom for sure, but she's the mom of a bunch of minor antagonists and one slightly more important antagonist, not any of the main characters.
But Big Mom is there. She's a mom for sure, but she's the mom of a bunch of minor antagonists and one slightly more important antagonist, not any of the main characters.
Like the rest of the characters on this, she's famous for being a mother.