you mean a UT (untouched) arceus, probably caught by the diamond/pearl event.
Still looking for: , Celebi, 4 Deoxys, , 17 Arceus, Tornadus, Keldeo, Meloletta, private message me, legendary trades can be negotiated, i have three extra mewtwos(pending), one extra of each RSE legendary(pending), and some others(extra hg/ss legendaries)
, Celebi, Deoxys, Arceus, Tornadus, Keldeo, Meloletta
games i own: FR(right before sabrina?), LG(was pal parking charmanders), EMERALD(just beat brawly), PEARL(not even done intro), PLAT(right before victory road), HG(team got loaned out, never saw guy again, right at Last Gym), SS(just beat falkner, EV training), WHITE, B2(beat first gym), Y(outside house for first time)
completed: White (just past E4)