Pets - Evolve ???

So I have Cloudhoof at level 300. It says select pets "2" star to sacrifice. It won't let me select them. Says none available. But I have a level 300 Pyrofraken and a level 300 Emberpaw. They all three say the same thing so what gives?

What lesser per do I need to level up to 2 stars to evolve my Cloudhoof?