In 1999, fifteen short years ago, the world had barely heard of Vin Diesel, and we were all worse off for it. Yes, he had done some brief but memorable work in Saving Private Ryan the year before, but we were still a little ways off from the first wave of Diesel domination. But 1999 was the year Diesel delivered one of his most memorable and enduring performances: the titular role in The Iron Giant.

Just watch the above feature (ripped from the DVD) that shows just how much of the heavy lifting Diesel did in creating the gravel-throated voice of the robot, which booms with humanity. The Iron Giant is a beautifully-made film from start to finish, but it hinges on Diesel's performance. Not just anyone could do that. Yet it took until 2014 for him to return to the voice-over booth for his already-heralded work in Guardians of the Galaxy as Groot, the living tree of few words.

Groot is an even simpler performance than the Iron Giant: literally all he can say is "I am Groot." But he says it a lot, and with different inflections each time, and Diesel apparently paid a lot of attention to how the walking tree-man is feeling each time he speaks, according to an interview James Gunn gave with IGN back in February.

"The ways in which Vin Diesel says 'I am Groot,' I am astounded," Gunn says. "Vin came in and in one day, laid down all these 'I am Groot' tracks, and he's a perfectionist. He made me explain to him with [every] 'I am Groot,' exactly what he was saying.....Then Vin would sit there and he would do it and he would it again and again and again, and his voice is so rich and so beautiful and he really opened up and was this character. It was amazing when we first put that voice in there how much the character changed and how much he influenced the character."

Gunn isn't lying. Diesel once again uses his most incredible asset—that sonorous voice—sparingly and beautifully in Guardians. And not only that, he's managed to record his lines in four other languages. See below for "I am Groot" in French, Spanish, Russian and Portuguese.