Manahive

Please specify which “Colossus” card you mean; there are several (e.g., “Darksteel Colossus,” “Steel Hellkite” is similar). For example, if you mean “Darksteel Colossus” (artifact, indestructible, huge creature), try:

• “Blightsteel Colossus” (artifact, indestructible, infect)
• “Metalwork Colossus” (artifact, big stats, cost reduction)

All are artifact creatures, colorless, with high power/toughness, fitting “colossus” theme.