Your search for "Swamp 303" revealed the following:
Swamp (301) (FIN) from Final Fantasy, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Fang Xinyu
Swamp (273) (AFR) from Adventures in the Forgotten Realms, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Adam Paquette
Swamp (143) (ARC) from Archenemy, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Susan Van Camp
Swamp (003) - Arena League Promo 2003 (PAL03) from Arena League 2003, available at 401 Games Canada. Rarity: Rare Finish: Normal Artist: Rob Alexander
Swamp (302) (Foil) (FIN) from Final Fantasy, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Sean Vo
Swamp (033) (Foil) (SLP) from Secret Lair Promo, available at 401 Games Canada. Rarity: Rare Finish: Foil Artist: John Avon
Swamp (033) (SLP) from Secret Lair Promo, available at 401 Games Canada. Rarity: Rare Finish: Normal Artist: John Avon
Tainted Isle (DSC) from Duskmourn: House of Horror Commander, available at 401 Games Canada. Rarity: Uncommon Finish: Normal Artist: Alan Pollack Card Text:T: Add C.T: Add U or B. Activate only if you control a Swamp.
Bayou (2ED) from Unlimited Edition, available at 401 Games Canada. Rarity: Rare Finish: Normal Artist: Jesper Myrfors Card Text:Counts as both swamp and forest and is affected by spells that affect either. Tap to add either B or G to...