Y ahya Abdul-Mateen II looked like a superhero long before Marvel cast him as one. He’s got an imposing nearly six-foot-three frame, a deep voice, a broad chest, and a blinding white smile. And on the blustery March day in Brooklyn when we meet up for a walk in the park, he’s also got an eight-month-old absolutely kicking his ass.  Buddy, the eight-month-old in question, is Abdul-Mateen’s new giant schnauzer puppy, who trots in front of us on rain-splattered streets with a comic, tongue-lolled devotion. “He takes his sweet time,” Abdul-Mateen, 39, quips as Buddy sniffs noncommittally and then continues on his way, lunging for bits of stale bread scattered for birds. Buddy’s paws are massive in an ominous way, flashing a growth spurt just over the horizon. His shiny black coat perfectly matches Abdul-Mateen’s ink-black patent trench. The duo look at each other with equal fondness. But the puppy phase isn’t for the weak.  “It’s still going on, man,” Abdul-Mateen says. “Buddy kickin’ my butt.…