67 known values for trail with current usage counts:

1. default (27217× used)
2. fluff (9468× used)
3. yellow_dots (5675× used)
4. red (2557× used)
5. blue (1594× used)
6. paws (1438× used)
7. fire (1312× used)
8. rings (1304× used)
9. green (1299× used)
10. earth (1064× used)
11. ice (945× used)
12. arcade (935× used)
13. red_neon (837× used)
14. stardust (709× used)
15. ice_dust (564× used)
16. blue_neon (564× used)
17. fire_dust (541× used)
18. sakura (517× used)
19. flowers (508× used)
20. shadow_dust (467× used)
21. magic (391× used)
22. autumn_leaves (390× used)
23. crimson (380× used)
24. digital_3d (308× used)
25. shadow_tail (303× used)
26. fire_tail (290× used)
27. abstract_3d (235× used)
28. elements (227× used)
29. ice_tail (222× used)
30. magic_tail (213× used)
31. magic_dust (198× used)
32. wish (176× used)
33. speedy (69× used)
34. black_and_white (67× used)
35. stars (65× used)
36. tech_path (59× used)
37. pollution (47× used)
38. tracks (45× used)
39. green_neon (43× used)
40. leaves (42× used)
41. feathers (37× used)
42. snowflakes (33× used)
43. siren (33× used)
44. aaaaa (29× used)
45. festive_tree (29× used)
46. treasure_map (29× used)
47. pumpkins (28× used)
48. zzzzz (28× used)
49. twinkles (27× used)
50. red_dots (26× used)
51. propulsion (25× used)
52. dots_inc (22× used)
53. lunar_fireworks (18× used)
54. bubbles (14× used)
55. ghost (9× used)
56. rainbow_light (9× used)
57. blue_plasma (9× used)
58. bomb_fuse (8× used)
59. rainbow_dots (7× used)
60. money_trail (7× used)
61. lucky_trail (7× used)
62. confetti (7× used)
63. red_plasma (4× used)
64. spacewar (4× used)
65. gold (2× used)
66. meteorite (1× used)
67. gold_dust (1× used)