Eddie from Emergency Exit has a particularly amusing (especially if you haven't read the story) example here.
Saya also uses this trope on this page while referring to the previous example.
In Gai-Gin, Foxy shows Gin some novelty taiyaki: "It's cakes! Shaped like penises! Man penises!"
In Girl Genius Zeetha is guilty of this at one point. It's put down to her spending too much time with Jaegers, which just shows that the Jaegers have too many examples of this trope to list.
Zeetha:You've got the brains, I've got the muscle, Violetta's got the sneaky! We can do anything! Violetta: The "sneaky"? You've been hanging around Jaegers too long.
At one point in Goblins, huge lizard-man K'Seliss says, "... There is battle happening right now all around me and I'm stuck in this pathetic hut like some... hut... stucky... thing!
Guilded Age: Frigg in general. Highlighted in her daydream during her attempts at diplomacy (without violence) with the gnomes.
Frigg: Sorry Ardaic! I tried my best, but someone accidentally killed them to death.
Red from Gunnerkrigg Court lapses into this when describing such esoteric concepts like rooms and chairs. "Sitty-downy things," indeed. This is implied to be a function of serious gaps inherent in the education process prior to becoming human, because while chairs are a foreign concept she jabbers off about some seriously advanced nonsense.
Happens frequently in Homestuck, since most of the characters are thirteen years old. Especially with John, whose Heir of Breath powers are consistently referred to as "the windy thing". Lampshaded:
EB: i'm going upstairs to the big platformy thing.
TT: The alchemiter?
EB: ??
TT: Try to learn the lingo.
It's a Running Gag that nobody knows what to call the "flappy doodad" that exists on a mailbox and has some trouble coming up with a description that someone else can understand. (The technical term seems to be 'signal flag', by the way, but somehow that's not very satisfying)
Dave ends up using this to captchalogue more items, the reason being that the number of the card the captchalogued item goes to directly depends on how the item is labeled.
Haley's brain feels "like a psion... did some psiony stuff." In fairness, Haley was having a large hangover at the time, and so couldn't come up with a decent metaphor.
Pebble from Pebble and Wren often talks in slightly grammatically-incorrect sentences, like "I don't want it to explosion my mouth".
Scary Go Round does this all the time, especially Shelley.
Example:
Amy: I think it's a vampire! Stab it with a stake!
Shelley: We can't do murders on it!
Another, laced with sarcasm:
Amy: I've not been this surprised since I discovered... something desperately unsurprising.
Parodied in the "Muffin the Vampire Baker" story. "I'm going to do my best to distortify the English languagism thingies." When Muffin hears that vampires can be killed by staking instead of baking, she declares she's now "Muffy the girl who sticks wooden thingies into vampires".
In "Anima: Resolution", it turns out Riff's Gadgeteer Genius notes are written like this:
The 'psionics-laced electricity' maked the D.F.A. behave wacky. Since the anima tapestry appears gone, the D.F.A. should operate normally now.
Riff: This is why I say "Let me check my notes. Just "me"!
Kris Straub's comics use this. In Starslip Crisis, sometimes this is future slang, and sometimes it's just "Fooly-fools!"
Sunstone has Ally describing her first S&M movie as having "porny exaggeration" and "costumey visual side."
Jules: Come along then. You can be my apprentice... or squire... or... whatever.
Van: What does a squire do, Jules?
Jules: I don't know; he squires. We'll look it up in the dictionary later.
In SwordCat Princess, Erica clumsily lies about how she obtained Kathryn's phone number, offering "Detective-ing?" as her clearly false answer (on the first page of issue #5).
Brunel: Where would science be without the Engine? Archaic! Puny! Boring! It doesn't bear thinking about! I'd be able to build gigantic iron ships, certainly—but could they fly? Lovelace: It would indeed be difficult... Brunel: Would Darwin be able to mess around with his, uh... barnacles he won't talk about? Lovelace: Um, that one I'm not sure about... Brunel: Would Faraday be able to that whatsis with the thingamajig?? Lovelace: No! No he would not! Brunel: Now get out there and do whatever the hell it is that you do!!
Wapsi Square has Castela, currently in kindergarten at the paranormal school, who slips back and forth between a five-year-old version of this and an occasionally startlingly-sophisticated and insightful, "mature", speech pattern.
In You Damn Kid, the narrator's parents get into an argument because Dad is looking for "the thing for cutting the things" and is angry that Mother doesn't know what he's talking about. "Imagine your parents not speaking for two weeks because Dad can't remember the words for 'toenail clipper'."
:Red Mage: We'd be better off using harsh language than the pathetic wooden pieces of... pathetic... weapons that these people call... weapons.Black Mage: Um...Red Mage: Shut up. I've been hanging out with Fighter all day. I could literally feel him sucking away at my... brain-thinky score thing.Black Mage: You mean intelligence?Red Mage: By Mordekainen's + 5/+ 5 wand of sorcery, he's lowered my INT score just by being near me!