Jerry
Awkwarrrd.
Jerry
Jerry (JP: ジェリー) is a monster that the protagonist encounters in Snowdin. Jerry is unique in that it has no attack of its own, but instead causes other monsters' attacks to last two seconds longer than normal.
Jerry appears to be a monster shaped like a flying saucer. It has three dull, thick spikes on the top of its head, some black spots, very long narrow arms, four legs, two rectangular eyes on the widest portion of their body, and swollen lips.
Jerry's traits are similar to the stereotype "That Guy." Examples include profuse arrogance, disrespect, informal language, poor hygiene (licking its hands and sneezing without wiping), and ungratefulness. These traits generally cause Jerry to not be a satisfiable person in general, which explains why only the "Ditch" option is present. However, if the protagonist tells a joke in a battle where Snowdrake is present, it finds it funny and may even ask for more jokes from them, having equally positive reactions from more of their jokes. This satisfies it to the point of being spareable.
Jerry's in-game function is that of a support member (e.g. Bard, Dancer), whose role is to bolster the offensive capabilities of other monsters. While support members are usually considered welcome additions to the party in most RPGs, other monsters are shown to dislike Jerry's presence. Jerry itself also dislikes other monsters, despite supporting them.[2][3]
Jerry does not show up in the True Pacifist ending credits.
- Ditching Jerry causes it to disappear, but it returns after two or three turns. Sparing all other monsters while Jerry is ditched ends the fight.
- Jerry can immediately be spared if the protagonist has high enough AT.
- When Jerry appears with Snowdrake or Chilldrake and the protagonist makes a joke, Jerry can be spared.
- Due to its high defense, Jerry is surprisingly hard to kill, and takes around nine hits to kill with weapons obtainable before or in Snowdin. This is because of a special rule at the end of its damage calculation that divides all damage dealt to Jerry by 5, giving it an effective HP of 400.
- Guys, it's COLD. Does ANYONE care? [Neutral]
- Why are we doing this? What a fail. [Neutral]
- Wow, you guys SUCK at this. [Neutral]
- SHHHH! I'm THINKING, guys!! [Neutral]
- Ka-SIGH. [Neutral]
- Hahaha! Say something else funny! [Joke at Snowdrake/Chilldrake]
- Haha! Wow! Drake, you suck! [Joke at Snowdrake/Chilldrake]
- Hahaha! Where do you get your ideas!?! [Joke at Snowdrake/Chilldrake]
- Well... can YOU give me a ride home? [Alone]
- Huh? Did they ditch me...? SOME friends! [Alone]
- Awkwarrrd. [Alone]
- So, like, what are you even doing? [Alone]
- The wi-fi here sucks. [Alone]
- Everyone knows Jerry. Makes attacks 2 seconds longer. [Check]
- Icecap appears. Jerry came too. [Encounter with Ice Cap]
- Icecap and Snowdrake confront you, sighing. Jerry. [Encounter with Snowdrake and Ice Cap]
- Icecap and Chilldrake confront you, sighing. Jerry. [Encounter with Chilldrake and Ice Cap]
- Jerry clings to you! [Encounter; unused]
- Jerry eats powdery food and licks its hands loudly. [Neutral]
- Jerry sneezes without covering its nose. [Neutral]
- Jerry tells everyone it has to go to the bathroom. [Neutral]
- Jerry lets out a yawn. [Neutral]
- Smells like....... Jerry. [Neutral]
- You and the other monsters ditch Jerry when it looks away! [Ditch]
- The other monsters celebrate Jerry's disappearance. [After Ditching]
- Return of Jerry. [If Jerry reappears during a fight]
- Jerry is wounded. [Low HP]

Jerry was designed by Magnolia Porter, creator of Monster Pulse. She also designed Monster Kid, Snowdrake, Ice Cap, and helped design Gyftrot.
In Chapter 2 of Deltarune, Terry is shown hanging out with a group of Ice Caps near the church.
- Jerry's official tarot card as Major Arcana XXI, "The World".
- When attempting to name the fallen human "Jerry", the response is "Jerry." and the name is allowed to be used.
- In the original release, the dialogue Jerry used when returning from being ditched was identical to Ice Caps when using Compliment. This was removed in a later patch.
- Toby has said on Twitter that he thinks all monsters in the game are good, except Jerry.[4]
- Although this tweet is likely meant to be interpreted as a joke, he may also be referring to Jerry's personality and mannerisms being negative and nearly irredeemable.
- The line "Return of Jerry" when Jerry reappears during a battle is a reference to the 1988 game Zelda II: The Adventure of Link, which includes the text "RETURN OF GANON" on the game over screen, even when the game's language was in Japanese (spelled as "GANNON" instead). Because of this, the sentence was intentionally left untranslated in the Japanese translation to keep the reference.[5]
- Jerry is based off a joke Toby made in high school about a fictionally annoying character named Jerry.[6]
- ↑
Jerry eats powdery food and licks its hands loudly.
— Battle narration - ↑
Wow, you guys SUCK at this.
— Jerry - ↑
Haha! Wow! Drake, you suck!
— Jerry - ↑
OK, Jerry is an exception
— @FwugRadiation on Twitter, October 06, 2015. Archived on November 26, 2015. - ↑ "In the English script, Jerry’s arrival is accompanied by the text “Return of Jerry”. Toby noted that this is a reference to the classic 1988 game, Zelda II: The Adventure of Link. Specifically, it’s a reference to the game over screen, which includes the text “RETURN OF GANON”.
The original Japanese version of Zelda II had a similar, English-language game over message: “RETURN OF GANNON”. To retain this reference, the translator left “RETURN OF JERRY” entirely in English in the Japanese Undertale script." — Clyde Mandelin, Legends of Localization Book 3: UNDERTALE, pg. 128 - ↑ UNDERTALE 10th Anniversary Stream - Day 1 (02:05:45) on YouTube