Hydro-Man, Fluid Felon — ruling 1

After the triggered ability resolves during your end step, however, you may tap him for {U}, even if he entered the battlefield this turn.

Hydro-Man, Fluid Felon — ruling 2

The 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.

Hydro-Man, Fluid Felon : règles, fonctionnement et interactions (MTG)

Hydro-Man, Fluid Felon is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

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 ": Add ." (He's not a creature during that time.)

How it works : Hydro-Man, Fluid Felon

Original English text — Wizards of the Coast / Scryfall

#1September 19, 2025· Wizards of the Coast
After the triggered ability resolves during your end step, however, you may tap him for , even if he entered the battlefield this turn.
No other card is named in this ruling.
#2September 19, 2025· Wizards of the Coast
The effect of Hydro-Man's last ability ends as your turn begins. There is no opportunity to tap Hydro-Man for once your turn has started.
No other card is named in this ruling.