I'll post my list in a bit...
TOTT:
Blue, Yellow, Silver (Japanese), Gold, Crystal, Sapphire, FireRed, Emerald, Pearl, Diamond (spare), Platinum, SoulSilver, HeartGold (spare), White (Japanese), White (Originally my main until it was stolen by YGO cheesedicks at my LGS), Black (new main after theft), White 2 (Japanese), Black 2, White again (spare), X (main, got it 2 days early thanks to a tip from this very board), Y (Japanese language, but US cart), Y again (French language, but US cart), OmegaRuby (main for ORAS), AlphaSapphire (foreign language on a US cart)>>20258873>random passerbyWell there's your problem...
As
>>20259056 mentioned, the Mamoswine was probably hacked. Passerby battles don't have hack checks like Battle Spot battles do.
That's why I avoid Passerby battle at all costs.
But then again, I ignore most non-Friend trades/battles if they show up on the PSS. 