DECHO is the romantic pairing of : Derby and Echo.
While it was never official, there were many episodes which showed Derby possibly being interested in Echo and even Echo being interested in Derby.
DECHO was first recognized in episode 14, season 2, Mr. Witness. After Derby tattles on Slab (only after being promised protection) Slab's punishment unexpectedly ends early and he seeks revenge, and Derby forces Mr. Tater to help hide him. Later that day it is announced in science class (by Tater) that Derby has moved to Atlantis and a new student from England(who is actually Derby, now in a version of witness protection at Finnegan), Simon will be joining them instead. With his English "charm" and accent, Echo falls for him, much to Adam's annoyance. Even when Adam tries to sabotage her asking Simon out by giving her false translation information, such as, " Out on a date" is British slang for " a rainy funeral" Echo gets an English Slang Dictionary and asks him out anyway and after realizing " Supper and A Film" means a date, he seems surprised and (after consulting the book) happily accepts. In the end, their date is ruined by Slab.
Episodes with either Decho moments or hints.
Mr. Honest : When Derby is finally able to lie, Echo tells Derby to ask her a question to see if she could lie,too (meaning that they are cured), so Derby asks if she finds him even the slightest bit attractive(?) and when she says yes, he looks happy, but then when she starts celebrating, saying she's cured( meaning she lied about finding him attractive), then he looks sad and disappointed.
Mr. Ballerina- After playing the prince in Swan Lake, Derby first asks Echo what she thought of his performance(meaning he cares what she thinks) and she says it was incredible and that she had never seen that side to him before, Derby is surprised and then happily accepts when she asks if he could give her dance lessons(saying he'd love to), she even uses a "slang term" Derby said earlier in the show, convincing him it is catching on.
Mr. Matchmaker : After finding out Slab's biggest fear (milk), Derby plans on dressing up as a milk carton for payback, but when Echo instead Suggests he help Slab(to make an enemy an ally) Derby decides to go with her idea right away (meaning Echo might have sway over Derby)
Mr. Moth : Derby seemed strangely certain that Echo could not have possibly flirted with Adam and was quiet determined to prove that it was not Adam, but the pheromones, (perhaps meaning he does not WANT to believe Echo actually likes Adam), and later seems quiet satisfied when he is proven right. Derby quote : "Echo is on her way over, i will blend in to my surroundings, as to not to influence the results, and observe quietly as she rejects you"
Mr. Witness : Echo has a crush on Simon (Derby's alter-ego) and he seems to like her too.
Mr. Discovery: During Echo's Dream sequence/Science project, when she is Marie Curie and Adam is Pierre, her husband, Albert Einstein (Derby) comes in and flirts with her and when Derby is in his dream sequence/science project, his girlfriend is looks like Echo.
Mr. Pixel: Even though Derby seems to have a crush on ivy, when she was basically worshiping him in the game, he didn't seem to pay much attention to her at all( meaning he may not like her all that much, and may just want to order her around and worship him) but the second virtual Echo starts dancing with Adam, he stops the hole game and gets mad.
Mr. Invisible : first when Echo tries to take a seat in history class next to her new crush, Derby( in the invisibility suit) sits there first and refuses to move, making Echo sit somewhere else (next to him), then, when Mrs. Byrne once again tries to teach the class about "The War of 1812", Derby, then Echo grown about it, then when Echo convinces Byrne that not only was there no war, but no 1812, Derby compliments her, sounding impressed. Later while Derby is trying to help Adam out of the Invisibility suit, Echo comes out after crying for a bit, and at first Derby is about to say something else when he notices how sad she looks and asks if she's okay, sounding genuinely concerned and when she says she would like someone to talk to, he says "sure, why don't we talk at your place" (sounding very sweet), but then inviso-Adam slaps him, then he says "Or i could just walk you home?", then Adam slaps him again, so then he "suggests" or i could walk behind you keeping a safe distance away, while making sure you get home safely, then when Adam does not slap him he thinks he's in the clear, then Adam slaps him, finally Derby just gives Echo cab fare, while looking disappointed and like he really does not want to. Echo looks disappointed too, when before she looked really eager to accept his first offer. Finally at the end, After Echo asks Derby if he could help find her prop sword, after Adam tries to take out the sword and succeeds (after Derby tried it first) Derby looks miffed(possibly because it was in front of Echo). This episode was important for many reasons,1. Derby showed genuine kindness, not only asking if she was ok, but actually wanting to talk about it, and not just to anyone, but to Echo(showing he really cares about her, 2. Even though he clearly wanted to, Derby decides not to spend time with Echo because of Adam(showing he does indeed care about their friendship) 3. Echo looked like she really wanted to talk to Derby and she asks Derby to help find her sword (meaning she trusts him and possibly likes him) and 4. Adam being a jerk and jealous of Echo and Derby.
Mr. Candy : After Ivy makes over Derby's costume, Echo says " Mamma like" ( insinuating she likes how he looks)
Mr. Hyde: When Derby tries to make his point to Adam by saying " But watching Echo in a tight, form fitting outfit, in a hot steamy room, stretching and contorting as sweat drips down every part of her body" he excuses himself to the locker, showing that what he said has an effect on him.
Mr. Double Date: Derby and Echo go on a double date with Adam and Hailey Straupperson. While it wasn't the most romantic of dates, when Derby thought Echo actually might like him he seemed excited and thought he might like her too.
Individual Character Profiles -
While at times Derby could be viewed as more of a villain then a hero, Derby's accidents are oftentimes mistaken for doing things on purpose and though he likes pranking, he has never intentionally pranked Adam or Echo. Derby often "seems" stupid or oblivious but as established in Mr. Hyde, Mr. Sleep, Mr. Moth and Mr. Elderman, he can and is exceptionally smart, he just has focus problems and gets bored and tired too easily(especially in Mr. Young's class). Although odd, it is also possible that the sleepier Derby gets, the smarter. Derby may not be the greatest friend at times to Adam, but he always( in his own way) tries to help him. As seen in the pilot, when Derby tried to warn Adam about Mrs. Byrne and when he helped him electrocute Slab, before Slab could beat Adam up and in Mr. Invisible, when after Derby throws mashed potatos at Tater,thus making it look like Adam did it ( since Derby was in the invisibility suit), but instead of letting him take the rap for it, Derby made a quick decision and makes it look like Tater instead did it, and Tater believes it, Derby can be a good friend and at the very least cares about Adam is his own way . It is very possible that Derby has identity issues. seeing as throughout the series he has: created two aliases ( Simon, a parody of Harry Potter, and Antoine Bolognese) and has dressed like a girl on several different occasions. It is also shown throughout the series, that Derby has mostly treated Echo politely and is nice to her, something that he fails to do with pretty much every single other character on the show( Adam, Slab, Tater and Ivy). Derby most likely has a crush on Echo, but just doesn't know it. Derby's hobbies include pranking, sleeping and gaming.
Echo is a very sweet, spirited and slightly geeky girl. Echo can be a bit oblivious, but only to certain things(like Adam's crush). Echo is very smart but can also be kinda lazy (like Derby). Also like Derby, Echo has a frenemy relationship with Slab, Ivy and even Adam at times. Echo is a vegetarian, an environmentalist and does charity work. Echo is one of the only two ( her and Derby) whose family is a mystery, while everyone else has established family,even Mrs. Byrne. Echo can speak an alien language. Echo often finds Derby odd but sometimes appreciate his oddness. Echo has dabbled in cheerleader, matchmaking and nursing.