Watch Will Arnett 'Let the Dogs Out' on 'Lip Sync Battle'

Alison Brie also pulls out the big guns – literally – for her prop-filled take on Jessie J's "Bang Bang"

Will Arnett kicked off his Lip Sync Battle with Alison Brie by – as host LL Cool J noted – "trying to answer that immortal question, 'Who Let the Dogs Out?'" Decked out in a purple track suit, the actor tackled Baha Men's canine-themed, Grammy-winning 2000 single, the only Top 40 hit to feature the lyric "flea-infested mongrel."

Arnett obscures his face with the microphone during the performance, possibly because he doesn't know all the lyrics. But his charisma wins out in the end. "You gotta be an incredible dancer," he tells LL Cool J after stomping around the stage. "Obviously I move like a gazelle. That was important."

Brie, Arnett's co-star in 2014's The Lego Movie, responds with a flirtatious take on Salt-N-Pepa's 1993 hit "Shoop." After being introduced by Cool J (who, in a verbal flub, hilariously introduces the actress as "the beautiful Alan"), Brie hip-swivels and air-humps her way through the track, nailing every line ("If looks could kill, you would be an Uzi"). "I love looking at men's bodies and thinking of how to describe them," she tells the host, with a playful stare. "'Yum, yum, chocolate chip, honey dip. I can think of some people that description might fit."

Arnett fires back with a childlike take on Tegan and Sara's Lego soundtrack smash, "Everything Is Awesome": performing "the robot" with a crew of construction workers, unveiling a Lego display with an anti-Brie picture.

A noble effort, but Brie brings out the big guns – literally – for her prop-filled take on Jessie J, Ariana Grande and Nicki Minaj's "Bang Bang." After a mid-song costume change, she makes good use of the track's machine-gun snares, shooting bullets at a WANTED poster of Arnett's face. "I've been memorizing that since before I was born," she boasts, then corrects herself. "But seriously, it was really hard work. I was listening to it every day in my car."