He has a resemblance to Edd, the differences being Eduardo has peach fuzz facial hair and a dark green button-up shirt with a light gray undershirt instead of a green hoodie.
Eduardo is very determined, mean, cruel, and abusive to Jon. Eduardo has a Brooklyn accent. The origin of Eduardo's rivalry with Edd is different throughout each episode.
In a flashback scene in Hammer and Fail: Part 1, a delivery man accidentally gives Edd Diet coke, while another delivery man accidentally gives Eduardo regular coke, when both realize there was a mix-up and discover the other's coke preferences in the process, Eduardo glares at Edd. After the flashback ends, Edd says, "And ever since then, it's just been ..." before he catches Tom using a drill.
In a flashback scene in PowerEdd, A young Edd and Eduardo attempts to make the best drawings for a class contest held by their teacher. Eduardo submits to a very detailed painting of a duckling while Edd submits to a quick sketch of himself as "Super Edd", yet Edd wins. Edd and everyone points to Eduardo, chanting "You're second place!" This incident may be the cause of Eduardo's hatred for Edd and is the reason why he always wants to be better than him.
Eduardo makes giant pieces of cardboard look like an extension to his house to make it look better, but the cardboard pieces fall over. He also laughs as he watches the destruction and damage made the ghost in Edd's house. When the ghost realizes he has the wrong house and moves to Eduardo's house, Eduardo swears revenge on Edd.
Despite being a jerk, he can be caring, as shown where he mourns Jon, attacks a Mutated Tom for attacking Edd, and reflects breaking up with Laurel. Despite the fact that Eduardo hates Jon and wishes that he was dead, he truly cares for him since he was devastated after Jon was killed by Tord's missile and was happy that Tom destroyed Tord's robot, thus avenging Jon's death.
- Eduardo (Saloonatics) - Eduardo's ancestor and leader of a small Mexican bandit gang in the late 1800s. Eduardo neither speaks nor understands Spanish, getting increasingly frustrated whenever he hears Marco speak.
- Old Lady Grandmado (grandmother)
- Hammer & Fail (Part 1, Rival Builders) (Debut)
- Hammer & Fail (Part 2, Rooftop Rumble)
- Space Face: Part 2 (Cameo)
- The End
- Casting Call (Mentioned only)
- No. 164 - info (August 8, 2011)
- No. 182 - Blast (August 8, 2012)
- No. 195 - Ex-Girlfriend (August 23, 2015)
- Eddsworld Comic No. 195