Mel Gibson and Girlfriend Grocery Shop in Malibu

Mel Gibson looks like he's hunkerin' down for the New Year ... with a Grizzly Adams beard and a big bag of rations.

Mel and GF Rosalind Ross did some serious damage in Malibu Monday in the aisles of Ralphs. He and his 27-year-old baby mama -- they have a 1-year-old -- also stopped by Vitamin Barn for some ... vitamins.

Gibson's coming off a successful movie -- "Daddy's Home 2." Well, now daddy's home for real and the eatin's good.