Erisolsprite is Jake English's sprite after being prototyped with Eridan Ampora's and Sollux Captor's corpses by Gamzee Makara. They have one of Eridan's zigzag horns and two of Sollux's in the midst of their combined haircut (the most notable feature being Eridan's streak), Eridan's glasses with Sollux's red and blue lenses, and one of Eridan's fins and his scarf before going into the typical sprite body and tail. The symbol is made of the wavy Aquarius lines combined by two parallel columns like the Gemini symbol.
Erisolsprite seems to take Sollux's self-loathing up to a very high level. He recognizes the fact that he was born out of (probably) the insane whimsy of Gamzee's inscrutable plans and hates himself and everything around him. He also seems to undergo personality shifts by the minute, contributing Eridan's strange (and often genocidal) remarks to (pre-blindness) Sollux's bifurcated shtick.