In A Cold Day In Miseryville, Heloise explained how the machine works in Techno Babble, with Jimmy and Beezy looking on in confusion. Heloise then deadpans something more simpler. Cut to Jimmy and Beezy in stereotypical classy scholar wear in complete understandment.
Jimmy's hallucinations in I Am Jimmy.
Heloise and Beezy's "eye-ball no blink contest" in "The Competition!"; Heloise's eyelashes grab Beezy's eyelids, and he screams out when she slams his eyelids closed.
Also the "The three of you! OUT OF HERE!" montage in the same episode, done by the same guy (especially when he mourns the loss of his egg at the end of the third skit).
"If you're watching this, you're well on your way to escaping...Just kidding! No one escapes! (cue Evil Laugh)"
There's Always a Hiccup is a laugh riot, but the best part is the absolute terror Beezy and Heloise experience after their Accidental Kiss, especially Beezy crying while washing his mouth out with soap and a firehose.
Heloise's facial expression while in her Stalker Shrine of Jimmy in the episode Pet Rocky
The opening scene of "Pop-sicles." Beezy in a chicken suit. Yes.
He seems to end up in that suit quite a bit. At the end of "Miseryville Marathon" as part of losing a bet, as a throwaway gag of him trying to break open a coconut by roosting in "Lucius Lost", and as a disguise in "Best Buddy Battle".
(Jimmy presses the button, which launches a missile that blows up a large observatory on a nearby hill)
Dr. Scientist: Apparently it destroys my house...
In Miseryville Marathon, Beezy bribes Heloise with a box of gold. She happily accepts...and dumps the gold out and begins playing in the box in a very un-Heloise like nature. It's extremely hilarious despite being a bit of an Out-of-Character Moment.
The Terrific Trio, when the three heroes are attacking each other. Power Squid cries out "AAAAH! IT STINGS! IT STINGS!!!" when Trouble Bubble Girl touches him directly in the eye with one of her bubbles.
In Heat Blanket Jimmmy, Lucius blasts off on his jetpack to spread more misery...from inside his house.
Lucius: The roof. Open the roof.
(Samy pushes a button. Crash!)
Lucius: Open the second roof! (Crash!) Open them all!
Lucius-mode Jimmy's actions in A Hair-Brained Idea count as either this or just scary. Special mention goes to him shoving an entire tray of cookies down Molotov's throat while yelling, "Have another cookie, CAT LOVAHHHHH!"
Gets even scarier/funnier when Jimmy seemingly comes to his senses, remarking that this isnt him... then driving up a CEMENT TRUCK full of cookies, shoves the cement slide itno Molotovs mouth, and feeds him until he explodes off screen.
Lucius repeatedly helping an old lady up and then dropping her as he tries to fight off Jimmy's personality, made even funnier upon seeing that Jimmy is doing the exact same thing on the other side of the road.
The monster with eyes all over its body:
Jimmy: What are you looking at?!
Monster: EVERYTHING MAN! (runs off sobbing)
Jimmy-mode Lucius finding a baby.
Mother: Please don't eat my baby!
Lucius: Eat it? I just want to kiss it! (kisses the baby's forehead)