Yeah go ahead and ask me something, it's not like I care.
—Eridan Ampora, apathizing.
Eridan Ampora is among the Twelve Homestuck Trolls, and like them, he fights for justice. He is a water dweller and is in a relationship with another one, Feferi Peixes.
Like the other eleven Homestuck trolls, he represents a Zodiac sign, Aquarius, and the thing is that there is one element per three signs, and it is Air for Aquarius (Along with Gemini and Libra).
Since that, he bears the element of Air (Along with Sollux Captor (Gemini) and Terezi Pyrope (Libra)).
His signature color is purple (AKA violet).
All we know when it came to sign-sharing is that he shares his sign with a famous basketball player, Michael Jordan.
He doesn't have his own country in a continent due to being a water-dweller, so he has own government near Bermuda. Excavated ground from underwater construction (see Amporaland) is used to expand Bermuda.
Both he and his girlfriend, Feferi Peixes, have their governments in Oceans, except she has hers in the Pacific.
Eridan Ampora has spent plenty of time trying to stop Adam Kokesh from being a (very) offensive person on YouTube.
Otherwise, he really doesn't care about a lot of things.
Eridan can be seen doing YouTube, DeviantArt, and 4chan.
Alongside Gamzee Makara, they were former bad guys, but they decided to redeem themselves; especially after hearing about the imminent threat known as Megatron.