With the release of "Night Lights", I think it's safe to say we have a decently good idea of what the timeline for Gum's scars are. This post will first analyze specific panels that show off what scars Gum has at the time and then I'll make a rough speculative timeline. And as a refresher, here are the scars Gum has by Book 1 and who game them to her.
So the earliest in the timeline is her scar from Phage. We know this due to her square head. Chances are that her bite mark was Gum's first scar
Next up is possibly Wick's scar depending on how the next EP plays out. In these panels we can see that Gum has her scars from Phage, Jumper, and Babs.
The lack of a Cherry scar in these panels leads me to believe that the flashback with Babs happens after Gum's first meeting with Wick
Given how Gum has Babs' scar in a moment of her life that took place before this scene, I personally believe that, as of right now, the hoof print is from a fight that took place early on in Gum and Babs' relationship and they made up by the time the above flashback happens. It could also potentially be an error, but until we get proof, I will assume Gum has her Babs scar in this sequence.
And then we have the scars from Candy and Sharps, which we have a firm timeline for.
By the time Gum quits she's already gotten almost all her other scars from her other girls. After she quits she gets her scars from Sharps here. Given how they're kissing here these scars were either an accident in the moment or Gums intentionally letting Sharps scar her for one reason or another.
So here is my speculative scar timeline:
Gum breaks things off with/moves on from Phage and Phage bites Gum in return
Gum meets Jumper after this, and Jumper gives Gum her head scar, likely via biting
And after that, Gum meets Babs and during a confrontation she gets stepped on, giving Gum her chest scar
She is then given an assignment to go after Wick and gets her burn scar during the fight
Gum meets Cherry and gets her head scar from a fight with the sea monster in the most likely scenario
Gum quits and Candy gives her her eye scar during the duel
Sharps permanently scratches up Gums back sometime after the two start dating
Quick edit but I realized that we actually currently have no way of knowing when Gum actually got her scar from Babs. We don't see her chest during the flashback nightmare with Phage so it's entirely possible Gum had her Babs scar and it was just covered. Oop











