These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Big Lipped Alligator Moment: In "Mario and Luigi Travel Through Time Part 2", after Mario and Luigi go to Morshu, we're randomly treated to a Disney Channel bumper for The Suite Life of Zack and Cody, immediately followed by some public access show with distorted audio, a purple tint, and sounds from a pig oinking. While random clips are to be expected in YouTube Poops, this particular example especially stands out in an otherwise coherent story-based Poop.
In the "Previously in" section at the beginning of "Bowser the Foodstealer 2", there's a clip from some cartoon of two girls water-skiing, and a clip from the 1981 movie "Grendel Grendel Grendel". For context, they have nothing to do with the previous "Bowser the Foodstealer" despite being in a Previously On section, any they don't they have any relevance to the rest of the Poop (except for a sight gag where a dolphin that the girls run over eventually lands).
Broken Base: Some say that the reason why the anonymous hacker(s) deleted his account was because many of his later videos were basically short gags based on Manipulative Editing and not story-driven like his more famous poops.
Some people were split to his style of Pooping being (relatively) coherent and relying on "clever" ways of editing, rather than adhering to the usual, more surreal and random style of the time. This even got to the point where some questioned if his works should technically count as YouTube Poopsnote It has been debated in the past on whether or not Flash Poops really are YouTube Poops, with some arguments saying that Flash Poops rely more on custom material rather than editing the original source. WalrusGuy himself even addressed this (and parodied the latter style of Pooping) in "The Only Youtube Poop WalrusGuy Has Ever Made Removed Because It's Horrible".
Special Effects Failure: In part two of "Mario and Luigi Travel Through Time", Morshu points out the door at one point, randomly having crab pinchers instead of a hand. While the effect is still funny either way, the pinchers glaringly disappear as the screen fades to black.