I may be overlooking something.

I have an alt character that has a Legacy chocobo whistle, but cannot summon their mount. Was wondering if there is a certain main story or side story quest that needs to be done to unlock mounts in general?

- It seems as though completing MS to level 15 doesn't do it.
- However, I have seen some that haven't yet made it to MS level 15 quests that can summon the chocobo already.
- The Achievement "My Little Chocobo" isn't connected to Legacy chocobos. Or is it?
- Joining a GC doesn't seem to be required.

Any ideas? Thanks in advance!