Mysterious Egg

{1}{b}{t}: Put a hatch counter on Mysterious
Egg. Then if it has 5 or more hatch counters
on it, transform it.
"So much potential, so much power radiating in this egg. I'm afraid to let it go, but I'm even more afraid of what will happen if I smash it. Once I figure out what to do with it, I'll write back."
—Last written text in Moveus's journal