Heres a list of the hidden helper quests i've done sofar, might be handy if people want to pick and choose them for convienience. List isn't finished because i had completed the 1st 10 before starting it, i will update when i've restarted on another char, or feel free to post any on this thread.
1.
2.
3.
4.
5. Kill 99 Wriggleleaf (thanks Canopener)
6.
7.
8.
9. Kill Mosscutter Queens, collect 55 messages
10.
11.
12. Kill 80 Mosscutter Queens
13. Kill Crag turtle, 30 msgs
14. Kill Crag crab, 30 msgs
15. Kill 90 Peryton
16. Kill Peryton, 40 msgs
17. Kill 90 Bugsharks
18. Kill 90 Bugdolphy
19. Kill 99 Stone gargoyles
20. Kill Stone gargoyle, 40 msgs
21. Kill 99 Flamehound
22. Kill Darksoldier, 40 msgs
23.
24.
25. Kill 99 Darkblader
26. Kill Darkblader, 55 msgs
I'd completed 23 and 24 before i realised i hadn't written down the quests.