Bluey's Course is the boss course of Snowflake Mountain and the second overall boss course in Diddy Kong Racing and Diddy Kong Racing DS. Serving as the tenth overall track in both games, Bluey the Walrus is raced here using the hovercraft and it is unlocked after all the races in Snowflake Mountain are completed for the first time. The course is a snow-covered and mostly downhill area with two tunnels and features trees as obstacles. Bluey is raced twice, first after clearing all of Snowflake Mountain's tracks, and again after completing all of their Silver Coin challenges (Balloon Touch Challenges in the Nintendo DS remake). The second time, Bluey is faster and giant snowballs from Snowball Valley will roll onto the track in the icy section shortly before the second tunnel.
In the DS version, snowmen were added to the track. The snowballs roll downward instead of sideways, and two snowballs were added at the beginning of the home stretch. The snowballs are also no longer absent in the first race. After completing both normal races, the player can take the Boss Touch Challenge, where the snowmen throw snowballs at the player and icicles fall from the ceiling in the tunnels.