If you’ve seen Guardians of the Galaxy (and judging by those high box office numbers, it looks like many of you did), then you saw that somehow the Marvel filmmaking team managed to take a tree-creature with limited verbal abilities and turn him into one the most beloved characters to hit the big screen in years.

Groot, voiced by Vin Diesel, is limited to speaking only three words — “I am Groot” — but his emotional depth knows not bounds. Though the non-human character was created through CGI (with some motion-capture performance references), he manages tug at everyone’s heartstrings, and this perhaps is in part because Groot’s on-screen appearance was inspired by someone very dear to the film’s director James Gunn — his dog, Dr. Wesley Von Spears.