Pet training schools:
1. Cap'n Threelegs' Swashbuckling Academy
(you need an account to see links)
Payment: Dubloons
Level restriction: Up to Lv 40
2. Mystery Island Training School
(you need an account to see links)
Payment: Normal / Tan Codestones
Level restriction: Up to Lv 250
3. Secret Ninja Training School
(you need an account to see links)
Payment: Red Codestones
Level restriction: Minimum Lv 250
Hope I interpreted the question correctly!