Madonna's Son -- Fast Times For Rocco Ritchie (PHOTO)

Surf's up for Rocco Ritchie ... Madonna's son has found his spirit animal, and it looks like it's Jeff Spicoli from "Fast Times at Ridgemont High."

Rocco was out in London with his dapper pop Guy Ritchie Thursday night, and the 14-year-old was rocking some long blond locks. Looks like he's been letting it grow since last summer ... when he was hanging with older sis Lourdes in the South of France.

We'd say like father like son, but this pic proves otherwise.

All Rocco needs are some tasty waves, a cool buzz ...and he'll be fine.