In the 2013 film *Frozen*, the majority of the improvisation came from **Josh Gad** (Olaf), though **Kristen Bell** (Anna) and **Idina Menzel** (Elsa) also contributed spontaneous moments and character traits that were eventually animated into the film.
The following are the specific scenes and lines that were improvised by the actors:
### **1. Olaf’s Introduction**
* **The Line:** *"Hi everyone, I'm Olaf and I like warm hugs!"*
* **Detail:** According to the directors, this was the very first line Josh Gad recorded. It wasn’t in the original script but was a spontaneous riff during his first session. The directors loved the "naivety and youthfulness" it brought to the character and used it as the foundational "spark" for Olaf's personality.
### **2. The "Impaled" Joke**
* **The Line:** *"Oh, look at that... I've been impaled."*
* **Detail:** In the scene where Olaf first meets Anna and Kristoff, he accidentally walks into an icicle that goes through his torso. Josh Gad ad-libbed the dry observation about being impaled. It was considered "darker" than typical Disney humor at the time, but the directors found it so funny they decided to spend the money to animate the physical gag specifically to match his ad-lib.
### **3. Olaf's Confusion Over Sven**
* **The Scene:** Meeting Kristoff and Sven for the first time.
* **The Line:** *"And who's the funky-looking donkey over there? ... [Kristoff: That's Sven.] ... Uh-huh. And who's the reindeer? ... [Kristoff: Sven.] ... Oh, they're both—oh. Okay. Makes things easier for me."*
* **Detail:** Much of this specific banter was developed through Gad’s riffing in the recording booth. He was encouraged to play with the idea that Olaf was trying to make sense of the world, leading to the "both named Sven" confusion that became a fan-favorite moment.
### **4. Anna and Elsa’s "First Time in Forever" Banter**
* **The Scene:** Anna and Elsa talking at the coronation party.
* **Detail:** While the major plot points were scripted, Idina Menzel and Kristen Bell were actually brought into the booth to record together for certain scenes—a rarity in animation. They improvised some of the "sisterly" dialogue and overlapping speech to make their relationship feel more authentic and less "stiff."
### **5. Anna's "Relatable" Quirkiness**
* **The Character Traits:** Drooling, snoring, and talking too fast.
* **Detail:** Kristen Bell pushed heavily for Anna to be an "unpolished" princess. Many of Anna’s most famous quirks, such as waking up with messy hair and drool or her socially awkward rambling, were not in the original "composed" character design. Bell improvised several of these personality "bits" in the booth, which the animators then incorporated to make Anna more relatable.
### **6. The "Ballroom with no Balls" Line**
* **The Line:** *"For years I've roamed these empty halls / Why have a ballroom with no balls?"*
* **Detail:** During the song *"For the First Time in Forever,"* Kristen Bell championed this specific lyric. While it is a part of the song, Bell has recently revealed in interviews (e.g., *Vanity Fair*) that it was a "cheeky" double entendre she and the team "slid under the radar" of Disney executives by insisting it simply referred to formal dance events.
### **Note on Kristoff and Sven**
**Jonathan Groff** often had to perform Kristoff's "Sven voice" (the voice Kristoff does for his reindeer) on the spot. While the idea that Kristoff talked for Sven was in the script, the specific delivery and the "psychotic" (as Groff calls it) back-and-forth between the two was often a result of him playing with different voices in the studio to see what made the crew laugh.