Kithkin in green-white, Merfolk in white-blue, Goblins in black-red, Elementals in blue-red, and Elves in black-green
OP16-038 Mr.3(Galdino) OP16-037 Mr.2.Bon.Kurei(Bentham) OP16-036 Roronoa Zoro OP16-035 Monkey.D.Luffy OP16-034 Monkey.D.Luffy OP16-034 Morley OP16-033 Boa Hancock OP16-032 Boa Hancock OP16-032 Buggy OP16-031 Trafalgar Law OP16-030 Antlerkov OP16-029 Smoker OP16-028 Jinbe OP16-027 Emporio.Ivankov OP16-026 Emporio.Ivankov OP16-026 Bunkov OP16-025 Inazuma OP16-024 Arlong OP16-023 Monkey.D.Luffy OP16-022 Monkey.D.Luffy OP16-022 Moby Dick OP16-021 Moby Dick OP16-021 If You're Coming with Me
While that may be the case, Underworld Breach offers players to cast an absurd number of spells from their graveyard that typically finds the player more cards
Its also a merfolk, and these tend to synergize with getting tapped, as many merfolk from Lorwyn and Lorwyn Eclipsed do
Old cards (those from old sets that are out of print) are often worth more, and their slow rise in value over time can probably be attributed to an a gradual increase in the number of MTG players
One way to think of things is that creatures provide value every turn that they attack or block