Cheapest priced copy (Double Masters): $0.35 at Card Kingdom, near mint, their price list as of .
Cathodion 
Artifact Creature — Construct · 3/3 · Uncommon · The List · #CM2-179
When this creature dies, add {C}{C}{C}.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
8 printings · $0.35 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 237 | Common | $0.35 | $0.49 |
| Commander 2014 | 234 | Uncommon | $0.35 | — |
| Commander Anthology Volume II | 179 | Uncommon | $0.35 | — |
| Modern Masters 2015 | 203 | Common | $0.35 | $0.49 |
| Mirrodin | 149 | Uncommon | $0.35 | $2.49 |
| The List | CM2-179 | Uncommon | $0.35 | — |
| Ultimate Masters | 226 | Common | $0.35 | $0.49 |
| Urza's Saga | 287 | Uncommon | $0.39 | — |
3 rulings from Wizards of the Coast
- 4 October 2004The ability is never a mana ability.
- 25 January 2011The triggered ability isn't a mana ability. It uses the stack and can be responded to.
- 25 January 2011You get the mana whether you want it or not. If you don't spend it, it will disappear at the end of the current step (or phase).