For my username, beginning with the letter D:
1. A (wild) animal: dingo


2. A (domestic) animal: dog


3. A Fruit: date


4. A color: dusty rose


5. A car model: Dodge Caravan


6. A Country: Denmark


7. A vegetable: daikon radish


8. A song: Don't Sleep on the Subway


9. A river: Danube


10. A recipe: deep-fried chicken


11. A movie: Donnie Darko


12. A book: Der 35 Mai


13. A Composer: Debussy


14. A Sport: diving

15. A name: David


16. A musical: ….no ideas.
17. A ballet: Die Fledermaus

18. An artist: Dali


19. An author: Dostoevsky


20. A plant: dogwood tree