68 known values for trail with current usage counts:

1. default (28858× used)
2. fluff (11307× used)
3. yellow_dots (6637× used)
4. red (3053× used)
5. blue (2052× used)
6. paws (1707× used)
7. green (1603× used)
8. fire (1306× used)
9. rings (1293× used)
10. earth (1080× used)
11. ice (942× used)
12. arcade (922× used)
13. red_neon (849× used)
14. stardust (716× used)
15. flowers (669× used)
16. ice_dust (649× used)
17. blue_neon (573× used)
18. fire_dust (564× used)
19. shadow_dust (553× used)
20. sakura (535× used)
21. shadow_tail (421× used)
22. magic (407× used)
23. crimson (396× used)
24. autumn_leaves (371× used)
25. digital_3d (367× used)
26. fire_tail (349× used)
27. abstract_3d (343× used)
28. elements (331× used)
29. ice_tail (306× used)
30. magic_tail (286× used)
31. black_and_white (218× used)
32. wish (215× used)
33. magic_dust (215× used)
34. stars (80× used)
35. speedy (75× used)
36. pollution (68× used)
37. red_dots (62× used)
38. tech_path (59× used)
39. tracks (49× used)
40. siren (47× used)
41. green_neon (45× used)
42. propulsion (43× used)
43. leaves (42× used)
44. feathers (42× used)
45. snowflakes (40× used)
46. treasure_map (38× used)
47. aaaaa (33× used)
48. pumpkins (28× used)
49. twinkles (27× used)
50. festive_tree (27× used)
51. zzzzz (25× used)
52. ghost (24× used)
53. blue_plasma (23× used)
54. lunar_fireworks (22× used)
55. dots_inc (21× used)
56. bubbles (19× used)
57. bomb_fuse (17× used)
58. red_plasma (16× used)
59. money_trail (15× used)
60. rainbow_light (14× used)
61. lucky_trail (13× used)
62. spacewar (13× used)
63. gold (12× used)
64. rainbow_dots (10× used)
65. confetti (10× used)
66. meteorite (6× used)
67. musical_notes (4× used)
68. gold_dust (2× used)