Welcome to Subeta! There are various ways for increasing pet slots, including some site events or prolonged membership (loyalty rewards) and slots which can be purchased with USD/CDC or sP, so the current limit you have is not the hard limit for forever c:

Useful Links:

What to do on Subeta? FAQ Useful general information for newbies Customise your dashboard Useful Custom CSS Builder Finding friends (Chit Chat) SubetaLodge (Offsite item database, pet colours etc.)