Mermaid Man, Aquatic Hero

Vigilance.
At the beginning of your upkeep, put 10 age counters on Mermaid Man, Aquatic Hero.
Then if there are 60 or more age counters on Mermaid Man, Aquatic Hero, transform it.
When Mermaid Man, Aquatic Hero enters, search your library for a card named Mermaid
Man's Belt, put it into your hand, then shuffle.