68 known values for trail with current usage counts:

1. default (27811× used)
2. fluff (9640× used)
3. yellow_dots (5932× used)
4. red (2745× used)
5. blue (1824× used)
6. paws (1485× used)
7. green (1445× used)
8. fire (1308× used)
9. rings (1304× used)
10. earth (1065× used)
11. ice (942× used)
12. arcade (928× used)
13. red_neon (836× used)
14. stardust (720× used)
15. ice_dust (579× used)
16. blue_neon (569× used)
17. flowers (562× used)
18. fire_dust (544× used)
19. sakura (519× used)
20. shadow_dust (475× used)
21. magic (390× used)
22. autumn_leaves (390× used)
23. crimson (384× used)
24. digital_3d (323× used)
25. shadow_tail (321× used)
26. fire_tail (305× used)
27. abstract_3d (264× used)
28. elements (257× used)
29. ice_tail (249× used)
30. magic_tail (237× used)
31. magic_dust (200× used)
32. wish (179× used)
33. black_and_white (74× used)
34. stars (71× used)
35. speedy (71× used)
36. tech_path (61× used)
37. pollution (52× used)
38. tracks (48× used)
39. leaves (41× used)
40. green_neon (40× used)
41. feathers (36× used)
42. siren (34× used)
43. snowflakes (31× used)
44. treasure_map (31× used)
45. propulsion (30× used)
46. festive_tree (29× used)
47. red_dots (29× used)
48. zzzzz (29× used)
49. pumpkins (28× used)
50. aaaaa (27× used)
51. twinkles (23× used)
52. lunar_fireworks (20× used)
53. dots_inc (20× used)
54. bubbles (14× used)
55. rainbow_light (10× used)
56. bomb_fuse (10× used)
57. lucky_trail (10× used)
58. ghost (9× used)
59. blue_plasma (9× used)
60. rainbow_dots (8× used)
61. money_trail (8× used)
62. confetti (7× used)
63. red_plasma (5× used)
64. spacewar (4× used)
65. gold_dust (3× used)
66. gold (2× used)
67. musical_notes (2× used)
68. meteorite (1× used)