Io: Ugh, what do you want? Io, the most volcanically active celestial body in the Solar System, and he is the most hot tempered.

Europa: Io, don't be mean.. Anyways, hey, cutie~! Europa, the most likely candidate for life in her sub-surface oceans, and she is also the most motherly of the Galilean moons!

Ganymede: Oi, m8! Ganymede, the largest moon in the Solar System, and the most Australian moon of Jupiter. He would literally pass as Australian man if he wasn't a moon.

Callisto: Oh... hey.. Callisto, the moon with the oldest known surface in the Solar System, and she is possibly the shyest moon of Jupiter.