52 known values for icon with current usage counts:

1. default (29763× used)
2. angel_wings (8280× used)
3. crown (6285× used)
4. joystick (6219× used)
5. moon (4020× used)
6. sakura (2183× used)
7. cat (1908× used)
8. dog (1655× used)
9. spider (1213× used)
10. pumpkin (721× used)
11. vampire (623× used)
12. headphones (549× used)
13. target (515× used)
14. sunglasses (510× used)
15. moustache (365× used)
16. coffee (307× used)
17. skill_issue (268× used)
18. panda (211× used)
19. snowflake (159× used)
20. santa (109× used)
21. pirate_flag (78× used)
22. wizard (74× used)
23. reindeer (72× used)
24. king (69× used)
25. octopus (62× used)
26. yeti (51× used)
27. rocket (50× used)
28. bad_bunny (49× used)
29. wanted (46× used)
30. lunar_dragon (45× used)
31. koala (36× used)
32. mountains (33× used)
33. ghost (30× used)
34. pyramid_eye (29× used)
35. planet (28× used)
36. bingo (26× used)
37. bread (25× used)
38. pirate (24× used)
39. cactus (18× used)
40. robot (18× used)
41. shark_attack (16× used)
42. fossil (15× used)
43. cute_bunny (15× used)
44. watermelon (15× used)
45. eliminated (13× used)
46. clover (8× used)
47. ankh (5× used)
48. pine_tree (5× used)
49. palette (3× used)
50. shooting_star (2× used)
51. jailbreak (2× used)
52. eleven (1× used)