Katherine (Kat) Murray

As Discovered in Kuriousity Killed the Kat
Kat, a mortal follows her friend Cassie to Camp Half-blood where she is decided as a mortal that can see through the mist.

She gets a room in the Big House and convinces Chiron to let her train as a half-blood. Unlike most mortals, as Kat discoveres, she can control wether Celestial Bronze passes through her or not and can manipulate mist.

Kat is as good as Hepheastus campers at Forgery and made herself a celestial bronze knife.