The rank of your OC is the prefix, and the Clan is the suffix!
Rank:
Kit: Crow
Apprentice: Thorn
Warrior: Bramble
Elder: Hawk
Deputy: Gray
Leader: Small
Queen: Fern
Medicine Cat: Moss
Clan:
ThunderClan: heart
ShadowClan: foot
RiverClan: claw
WindClan: fur
SkyClan: tail
BloodClan: pelt
StarClan: nose
Rogue/Loner/Kittypet: song
Comment the name you get! :)