Lead singer Adam Gontier has stated that while he was addicted to the painkiller OxyContin, he was abusive and angry and had no idea who he was anymore.

[10] Bassist Brad Walst spoke to Billboard about the song stating, "I remember saying [that] that riff would be great heavy.

Writing for Melodic, Kaj Roth praised "Animal I Have Become" as "really good" and a "great ... single" from the album.

[15] In a review of One-X for The Lewiston Tribune, journalist Nate Gibb named the song as "catchy tune" with thick guitars and "straightforward beats.

"[16] Similarly to Gibb in his review, AllMusic's Corey Apar singled out "Animal I Have Become" as having "a slight singsongy chorus to complement the track's thick riffing.

"[17] J. Krueger of Consequence.net remarked, "it's a tune built to get stadiums, festival sites, and biker bars on their feet and moving, and it does so damn near flawlessly," praising the song's chorus and "syncopated guitar riff.