Eduardo Rivera (voiced by Rino Romano) was first introduced as one of the next generation of Ghostbusters in Extreme Ghostbusters.
He seemingly a lazy, sarcastic and somewhat clueless character, Eduardo nevertheless makes himself an integral part of the team by being determined and reliable. Eduardo, along with Garrett Miller, resembles original Ghostbuster Peter Venkman in that, like Venkman, Eduardo is sarcastic, has a penchant for pursuing attractive women, and is generally unscientific and constantly spouts pop culture references. He also reads "J. N. Kline" young-adult horror novels.
Eduardo has a long-running subplot dealing with a love/hate relationship between him and Kylie Griffin, although it is very much revealed "In Your Dreams" that he has intimate feelings and dreams about her. These feelings are further enforced in that he is usually the one to rescue Kylie from dangerous situations, and vice versa, in several episodes. He once said to Kylie herself that nothing was going to happen to her "while [he's] around". In fact, in the episode "Darkness at Noon" he outright admitted to Kylie, who was possessed by a ghost at the time, that he felt an attraction of sorts when he saw her for the first time and even showed the intention of kissing her when Kylie asked him to. In "The Unseen" he takes the rap for Kylie's mistake, not wanting "the worst day of her life to get any worse".
In "Rage", Eduardo reveals to have an older brother, Carlos "Carl" Rivera, an NYPD officer who is angry with Eduardo for not being a police officer like the rest of their family, and thinks the Ghostbuster are a scam, which is why Eduardo kept his job a secret. In the same episode it is also implied that his father is dead (or at least retired) as he and Carlos refer to him in the past tense during a heated argument. In "Fear Itself", it is revealed that Eduardo has a fear of death (specifically his own). He has a vicious rivalry with Slimer, but has ended up working with the ghost, and volunteered to save him in "Slimer's Sacrifice".
He also has an on the surface rivalry with Garrett with the two often mocking each other and attempting to one up the other. In spite of this as the series goes on the two seem to have the closest thing to a friendship even though Garrett's enthusiastic personality completely contrasts Eduardo's cynical attitude. (The official website claimed he slacks off due to fear of failure.) Despite all his cynicism and slacking he demonstrates a reasonably high level of intelligence as in the episode "Eyes of a Dragon" he states how the proton aspect of light works to Kylie and later on how to defeat the ghost of that episode. Eduardo was also the one to smash a cursed orb, causing the eye-stealing ghost to disintegrate in the episode "The Unseen" and also continued the incantation that destroyed the demon of an alternate dimension in which he, Roland Jackson and Kylie were imprisoned in the episode "Casting the Runes". Eduardo has also exhibited bouts of jealousy whenever Kylie seemingly flirts with other men and in "Till Death Do Us Start" he showed signs of sheepish nervousness when asked if he and Kylie were together.