First pitch of the World Series is just hours away ... and Shohei Ohtani is hoping his dog, Decoy, gives him some good luck -- rocking a letterman jacket with his pooch's face on it!!

Ohtani pulled up to Game 1 in Toronto in style, rocking the tan letterman jacket with tan pants, New Balance shoes and his own custom Beats headphones.

If you're familiar with Dodgers baseball, you know Decoy is a popular figure in the fanbase. The team even had a bobblehead night featuring Ohtani and his dog ... who even got the chance to "throw" out the first pitch!

Shohei's gotta be hoping his four-legged friend helps get his team four wins ... as they look to become the first back-to-back World Series champions since the New York Yankees, who won three in a row from 1998-2000.

The 31-year-old will only have to worry about hitting for the first three games, as he's not anticipated to take the mound until Game 4 in the City of Angels.

We only got one question ... any chance that jacket gets put up for sale?!?