Mandatory neck tattoo? Wtf ... ?
Although I don't stick with the idea that Bill Roberts / Ink might do some genetic/ bio-chemical/ medical engineering on his zeds, I hav no trouble in thinking of a madman that, also being a psycho, a killer and an insane madman, he might be able to do bio-engineering of whatever kind. It only depends on the time where the button was pushed making him a madman; if he was kind of educated or trained as this kind of engineering-dude before having become an Hannibal-Lecter-clone, he might be able to use his skills form his former life ... And unless zombie-ism does not stop him from using such skills, here you go: a psychic madman-zombie doin' zombie-engineering ... Why not?
Again: I don't of this as being solid, nor even valid for the WA-verse, but in other zombie-stories I could imagine something like this ...

All the best!
Liam