Cheapest priced copy (Marvel's Spider-Man): $0.79 at Card Kingdom, near mint, their price list as of .
Hydro-Man, Fluid Felon 
Legendary Creature — Elemental Villain · 2/2 · Rare · Marvel's Spider-Man · #250
Whenever you cast a blue spell, if Hydro-Man is a creature, he gets +1/+1 until end of turn.
At the beginning of your end step, untap Hydro-Man. Until your next turn, he becomes a land and gains "{T}: Add {U}." (He's not a creature during that time.)
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
3 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Marvel's Spider-Man Promos | 33s | Rare | — | $0.99 |
| Marvel's Spider-Man | 33 | Rare | $0.79 | $0.49 |
| Marvel's Spider-Man | 250 | Rare | $0.79 | $0.99 |
2 rulings from Wizards of the Coast
- 19 September 2025After the triggered ability resolves during your end step, however, you may tap him for {U}, even if he entered the battlefield this turn.
- 19 September 2025The effect of Hydro-Man's last ability ends as your turn begins. There is no opportunity to tap Hydro-Man for {U} once your turn has started.