Aquarius was created by Roy Thomas and Sal Buscema in 1969 and first appeared in The Avengers #72.
A new Aquarius has recebtly appeared in the pages of The Amazing Spider-man
The first Aquarius was Darren Bentley, and was based in San Francisco. He aided the Zodiac's attempts to seize the Zodiac Key as well as trying to kill all Manhatten's inhabitants as a sign of their power. Along with the other leaders, he was captured.
He was later given the ability to turn into the other members of the original Zodiac by the demon, Slifer. The demon later kills him.