"Holly Jolly Secrets Part I" is the nineteenth episode in the third season of Adventure Time. It is the seventy-first episode overall.
Finn and Jake are trying to dig up a treasure Jake had found in the Dump and had buried without opening. When they get to the treasure Finn recognizes it, saying that he saw Ice King with it and burying it in a pile of boogers in the Dump. So they see that inside the suitcase is a bunch of tapes belonging to the Ice King and make plans for a secret tape watching.
Jake puts up flyers to warn people that the tape watch is for Finn, Jake, and BMO only but the Ice King, while trying the William Tell trick on Gunter, sees one and goes over to the Tree Fort. At that very location Finn and Jake start to watch the tapes and see that they are video journals and get bored soon. After some snack making Finn and Jake think there might be a secret code hidden in the message.
To crack the code Finn and Jake call up Princess Bubblegum, who is the 'smartest person' they know, but the line is interrupted by the Ice King who wants to watch the tapes too. BMO sees Ice King from a window and warns Finn and Jake who hang up on the Ice King. After caught up, he summons huge snow drifts that completely cover the Grass Lands as Jake starts to scream.
- This episode was on Cartoon Network's 2011 Christmas programming event.
- This episode is a two-part Holiday Season Special.
- This is the second pair of episodes that are considered to be two parts of the same storyline. The first pair was "Mortal Folly" and "Mortal Recoil."
- If you slow down the first portion of the Ice King's secret tapes that Finn and Jake fast-forward through, you can hear the following:
- "Diary, I've been meaning to tell you something insanely private, but darest I? I... love... to... ugghh! Fill my bathtub full of milk and sit in it like I'm a magic angel. There, I said it. The white of the milk is so dense, and when I poke my little toes out from under the milk they startle me and I giggle. Hee hee. I giggle, diary! Hee hee. They're my own toes, yet I giggle. And then I fall asleep, and the milk curdles and I get all stinky and sticky. Disgusting, diary. I'm disgusting! I'm disgusting! I'm disgusting and I smell like curdled milk! *cries*...anyway, back to the Turtle Princess."
- "This reminds me of a time that I got stuck in my bathroom. There was this squirrel, don't ask. Anyway, long story short, imagine me crouched down on the kitchen floor talking. I'm talking to the toilet paper. Ha ha ha! I'm like, 'Hey, guys! Who wants to go on an adventure?' And the toilet paper's like 'what?' You're my best friend, Diary."
- "I'm a tough man. A tough, icy man. A king. A tough, ice, kingy man. Oh yeah. Look at these guns. Look at these guns. Look at these guns. [sighs] 10. 24. 38. 45. Guns guns guns. Here comes the gun show. Pow pow. [inaudible] pow pow. Pow pow [inaudible]. Guns. Yeah. I could shoot cannonballs with these arms. Shot em around the world. Boom! I could level a rich kid's mansion with these puppies! Ah, my two beefy weapons. Beef and Beefier. Ah, look at those. Pure beef. Maybe I could rob a bank with my glutes. Wouldn't that be a trip? My arms walk into a bank: 'Gimmie all your money! Or I'll squeeze ya!' Ugh! Cause it's a gun show. I'll be the Money King once I get all that money! Yeah. Yeah, Money King. The king! Do you hear me? The king. [Drunk?] and unsatisfied. And lonely. I'm so lonely. Okay. Let's go. 1! 2! 3! 4! 5! 6! 7! 8! 9! 10! 11! 12! 13! 14! 15! 16! 17, 18, 19, 20! 21, 22, 23, 24, 25, 26, 27, 28, 29, 30! 31, 32, 33, 34, 35...' [continues counting as Jakes speaks over him]
- This is the first episode in which it is implied that the Ice King had met BMO.
- BMO's alarm for Finn's bath time sounds like a car alarm.
- A skull that resembles the Lich is mounted on the wall when Finn, Jake, and BMO go look out the window.
- The bearskin in Finn and Jake's living room has three eye sockets, which means the bear had three eyes.
- Finn said that one night while Jake was away at Lady's house he was dancing in the woods but Finn was in the woods during the day.
- In the Ice King's Penguin Dance Party Video, there are triangles attached to two strings with letters on them, spelling the words "Happy Birthday," indicating that he recorded it during his birthday.
- When Finn and Jake are watching the tapes for the third time (after Finn says "We need to find his secrets faster") the green and blue bowls with candy change places two times.
- The phone cord could not have stretched all the way down to the window.
- The phone changes places two times, one being when it appears in front of the window and Finn hangs up. It is not there anymore when Ice king uses his powers and the scene zooms in to the inside of the house.
- The other bearskin that was seen on the floor when they first go look through the window is not there anymore when BMO tells Finn and Jake that Ice King was on the phone outside.
- In the final scene Finn and Jake are lying down in front of the window instead of facing it backwards as they first were.
- There is not normally a tape deck installed on BMO.
- In the scene where Finn, Jake, and BMO went to look out the window Finn appeared much shorter than usual because BMO was all the way up to the top of Finn's leg in height.
- While watching the videos, Finn and Jake are on the floor eating Christmas-themed foods such as a substance that looks like Figgy Pudding and rolls.
- The title card shows Finn, Jake and BMO setting traps outside the chimney possibly waiting for the Ice King to come down. Jake's outfit reflects Jewish design; the small hat is possibly a Kippah (Yarmulke) and the scarf is a Tallit.
- When Ice King and Gunter are in the forest for target practice, this resembles William Tell shooting the apple off of his son's head.
- When the title shows, the design and outline of the title references to A Charlie Brown Christmas.
- Finn's statement in "Too Young" that he does not bathe is once again contradicted when BMO's alarm clock goes off, saying it is Finn's bath time. Though, to be fair, he did avoid it this time.
- Finn says, "Well then..." The same way in "To Cut a Woman's Hair."
- We also saw the Ice King exercise in the episode "Loyalty to the King."
- In this episode it seems that Ice King's diary is a video diary different from the first diary where he writes.
This episode was censored in some countries. See Censorship of Adventure Time for more information.