This article focuses on the interactions between Everyone and Carlo Debris.
Overview
Carlo's relationship with the engines is one of little respect from either side. Carlo tends to show very little to no respect to the engines. Throughout the series, Carlo insults and ridicules the engines on a regular basis. Because of this, he is disliked by almost all the engines. Carlo also often has negative interactions with the people of Sodor as well, often threatening or heckling them.
Dex and Winslow
Dex and Winslow with Carlo.
Dex and Winslow are the only people who get along with Carlo. They serve as his bodyguards throughout the series, and they each seem to be able to stand each other.
In Rosie, Winslow was seen behind Carlo when he was shouting derogatory comments at Rosie, Hank, and Kurt, possibly trying out for the position of his bodyguard.
In Henry and Kurt, Dex and Winslow were shown as Carlo's new bodyguards. They did exactly what Carlo told them to, even pointing guns at The Fat Controller at one point.
Diesel 10
Carlo giving Diesel 10 his instructions.
Carlo and Diesel 10 seem to have a mutual dislike for each other, as Carlo obviously does not like to put up with the large olive diesel, and Diesel 10 doesn't like being told what to do.
In Rock-Star, when Harold asks for Diesel 10 to help with the rockslide blocking The Flying Scotsman's path, Carlo sends Diesel 10, but not before giving him instructions. During these instructions, he calls Diesel 10 a "sulking iron wretch" but gives him permission to tear it to shreds. However, he also calls Diesel 10 the Lumberyard's "branch clearing specialist" instead of a derogatory term, possibly hinting at some level of respect towards the large diesel.
Henry
There is no denying that Henry and Debris deeply hate each other, because of Henry's love for the forest he strongly resents Carlo's lumber business. In the episode, Henry and Kurt, Carlo blames him for being behind on quota.
Duncan
In All the World's a Stage, Carlo and Walter Sliggs heckle the play together, with Carlo calling Duncan a "clumsy yellow dingbat with feminine qualities".
Hank
Carlo shouting at Hank and Stanley with Dex and Winslow.
Carlo frequently refers to Hank as "the star-spangled twit." Although he constantly shouts and ridicules the American Berkshire, he is well aware that Hank is the strongest engine at his disposal. Hank, however, is not afraid of Carlo and knows "his bark is worse than his bite."
Harold
Harold attempting to get Carlo's help with a rockslide.
In Rock-Star, when The Flying Scotsman's path was blocked by a rockslide, Harold flew to The Lumberyard to ask for Carlo's assistance. However, Carlo had his bodyguards point their guns at Harold and told him he cared nothing for Harold's "flying circus". However, he agreed to lend Diesel 10 to help with the rockslide.
Kurt
Kurt, Carlo, Hank, Dex, and Winslow in the Lumberyard.
Kurt and Carlo's relationship is one of little to no respect from either side. Despite the fact that Carlo considers Kurt a useful deforestation machine, he still commonly insults and shouts derogatory comments at him. In return, Kurt also commonly ridicules and speaks snarkily to the foreman.
Rosie
Carlo shouting at Rosie.
In Rosie, when the little pink engine was sent to help the Narrow Gauge Engines, one of her assignments was to pick up some important timber and supplies from Carlo's company to repair a damaged bridge. Although Rosie tried to upbeat and courteous, it had no effect on Carlo, who continued to be the rude and audible.
Scott Wallis
Scott formerly worked for Carlo at the Lumberyard. However, when he accidentally threw a hatchet through Carlo's office window, Carlo fired him on the spot.
Sir Frederick Aura
In Snow Blind, Carlo is revealed to be smuggling weapons through his lumber business for Aura. He seems to have reservations about this deal, as he sends Diesel 10 to "even the playing field" against Aura's thugs. He also sends the message that this is the final shipment, as he dislikes doing business with a sinister, secretive, war mongering simpleton.
In Swashbuckler, Aura threatens Carlo and says that someday he will change his behavior, but Carlo is mostly unfazed by his threats.
Splatter and Dodge
Carlo shouting orders at Splatter, as well as Hank and Stanley.
Carlo is not fond of Splatter and Dodge but the two were leased to him cheap by the Fat Controller after their respective mishaps in Splatter and Dodge. In order to keep his enteprise going, Carlo will take whatever he can get, but that doesn't mean he'll treat them right.
Stafford
In Henry and Kurt, when Stafford accidentally collapses a shed onto Splatter and Dodge, Carlo grows angry with him and proclaims that Stafford is hereby banished from the Lumberyard.
Stanley
Carlo does not appreciate Stanley's presence anymore than he appreciates anyone elses's. Stanley and Hank often crack jokes about Carlo right under his nose, which can really set him off. Stanley, however, is willing to question Carlo's irrational and irritable behavior which often leads to trouble!
In Henry and Kurt, Carlo insulted Stanley by calling him a "jovial nimrod". He then ordered Stanley and his friend Hank to haul some lumber, which led Stanley to wonder why he and Hank are always insulted whenever they recieve their orders.
The Fat Controller
Carlo insulting the Fat Controller with Dex and Winslow behind him.
In Henry and Kurt, the Fat Controller paid Carlo a visit. Throughout the meeting, Carlo constantly insulted the Fat Controller, calling him names such as a "lackadaisical bureaucrat" and having Dex and Winslow point their guns at him. The Fat Controller mentioned that he was growing tired of Carlo's idle threats, but muttered that he would prefer if Carlo would keep them idle. However, the two soon came to a mutual agreement, in which Carlo would lend the Fat Controller some lumber for The Little Western Extension in exchange for providing Carlo an area of overgrown forest near The Main Line. Carlo later remarked that it was a "displeasure working with him."
Carlo also hosted the Fat Controller's meeting with the other business people of Sodor at Last Haven. At the time however he was battling his mistreated workforce, who in turn rebeled against him during the meeting, putting all the attendees in imediate danger.
The Flying Scotsman
In Rock-Star, when Harold asks for Diesel 10 to help out with a landslide blocking the Flying Scotsman's way, Carlo states that he cares nothing for Harold's "flying circus". However, Carlo later sent Diesel 10 to help out with the rockslide nevertheless.
Walter Sliggs
Sliggs and Debris heckle the play together.
In All the World's a Stage, Carlo and Sliggs meet in the stands during the Narrow Gauge engines and The Thin Controller's performance of Hamlet. Debris calls Sliggs a "grease-ridden oil slick" and Sliggs responds by saying that Debris smells like "sawdust and long periods of sadness". However, the two still sit by each other during the play and seem to enjoy heckling the play together.
Wilbert
Carlo shouting at Wilbert.
Wilbert is the only engine thus far to recieve Carlo's praise and be respected by him.
In Wilbert the Lumberjack, an accident caused by slippery rails inevitably makes Wilbert crash into a dead tree the lumberjack's chainsaws couldn't even cut down. Although he had been rude to Wilbert prior, Carlo suprisingly congratulates Wilbert and dubs him "The Lumberjack of the Forest of Dean."