He is seen in The Legendary Starfy right before Mega Mashtooth's battle and you play as him in Mega mashtooth's Final stage where you have to push the moon back at him. He is this way because all your allies and the Trio (Ronk, Papes, and Snips) give him hope (or the power of friends, as mentioned before his 2nd palace stage.)
Super Starfy is Starfy glowing green and blue. Due to the hope bestowed upon him (see above).
Aparently, he also has super strength due to the fact he can push Bunnera's moon in the fight Mega Mashtooth.
- when he is fighting mashtooth, it's like your in water. So you can't use shooting star. Also, it's the same as being in water but your stronger. Because you can push bunnera's moon. And mega mashtooth pushes the planet at starfy again after the first time. Except, this time, it's STRONGER. So, starfy is good game and bye! By the way I added to SHOOTING STAR. And, BYE!!!