What it does
Baby-Doll Eyes drops the target's Attack by one stage before almost anything else moves. Priority +1 means it acts ahead of nearly all regular moves — only moves with +2 priority or higher (like Extreme Speed and Shadow Sneak variants) beat it to the punch. That timing is the point: you're cutting the threat before it hits, not after.
One Attack drop is roughly a ×0.67 multiplier on the target's physical output. A hit that would have done 75% HP now does closer to 50%. That's the difference between a KO and surviving to act.
Who runs it
Umbreon runs Baby-Doll Eyes at a 17% rate. It's a defensive, stall-oriented Pokémon — it's not trying to win via damage output. Baby-Doll Eyes fits its gameplan because it extends the number of turns Umbreon can absorb physical hits, which is what it needs to run its recovery and attrition loop.
The typical Umbreon set pairs Baby-Doll Eyes with Foul Play, Moonlight or Wish, and a support move. Once the target's Attack is down, Foul Play's reflected damage also decreases — which sounds counterintuitive, but the goal is to stay alive long enough to outlast, not to burst the opponent.
How to use it
In doubles, you have two opponents to target — aim at whoever is currently threatening your team with physical damage. A Garchomp or Urshifu in the lead is the obvious call. The Attack drop sticks for as long as that Pokémon stays in, so you're buying defense for multiple turns from one action.
The priority also means slower Pokémon get their drop in before faster opponents can act. You don't need Speed to get this off first — that's one of the reasons it's on Umbreon despite it not being particularly fast.
Tips & strategy
Baby-Doll Eyes does nothing against Special Attack. If the opponent pivots to a special attacker, you need a different answer. Recognize when the physical threat is no longer the priority and switch plans.
Abilities like Clear Body, White Smoke, and Full Metal Body block stat drops entirely — Baby-Doll Eyes will fail outright. Check the opponent's ability before committing the action.
The drop stacks. You can hit the same target multiple times to reach -6 Attack, though in practice two or three drops is usually enough to make physical hits negligible. Don't waste turns stacking it if the opponent can just swap.