List of Easter eggs
Easter eggs are intentional hidden messages, inside jokes or hidden features in video games and other media. The Legendary Starfy series features a few Easter eggs. Easter eggs are not to be confused with cameos or glitches.
- When playing a tune in the Sea Jams, a shocked Starfy can occasionally be seen coming out of Wotsaruto's Tone of Ocean instrument among musical notes.
- Playing "Tone of Ocean?" in the Sea Jams will cause only shocked Starfys to come out of Wotsaruto's Tone of Ocean instrument, likely because it is a badly out of tune version of the series Title Song (i.e. "Tone of Ocean").
- Funazou calls Starfy "Stalock Polmes" スタロック・ポームズ; this is a reference to Sherlock Holmes. Funazou also refers to Moe as "Kyotsun-san" (Japanese: キョトスンさん); which is likely a play on Sherlock Holmes' assistant Watson. Funazou continues to refer to Starfy as Stalock-sensei in Densetsu no Starfy 3.
- After beating a boss, there is a one in ten chance that Moe's siblings will appear in the background during the dance instead of the fish. 
- In the Sea Jams, playing "Yanki Kigurumi" (page 3, second to last tune) causes Moe to apparently sing using the microphone. He looks like he is laughing and two jagged flashes of 'lightning' can be seen above him. Starfy meanwhile, starts running back and forth with a shocked expression. Stopping the tune puts Starfy and Moe back to normal.
- The layout of map 8 (which can be viewed with the Nintendo Official Guidebook) of Large Tree's Forest (Stage 5)'s area 5 in Densetsu no Starfy 2 has 'floor blocks' in the air that resemble a person jumping up with their arms and legs pointing upwards. This is the last map before the boss battle with Numan.
The 'jumping person' in Large Tree's Forest (image from Nintendo Official Guidebook).
- Under unknown circumstances, after a boss battle and during the dance, a giant angry non-animated version of Moe with the front hinge of his shell open will move across the screen. It replaces the fish.
- In the Sea Jams, playing Boss Battle, Defeat Ogura, Jashin Evil, Minigame 2, Starfy Dance or Tone of Ocean Rock changes Starfy and Starly's guitars to more fancy ones that look a little like the Legendary Guitar. Starfy's is red, and Starly's is blue. Starfy, Starly, Wotsaruto and Moe also start to wear sunglasses. Moe starts to wear a black wig. Things turn back to normal when the tune is stopped.
- The Staff Credits text can be paused by holding Select.
- The Makaika Group seem to be a reference to the Makai Club of Japanese wrestlers.
- Starfy, Moe and Starly pull off expressions when they are touched on the title screen, with different expressions between the initial and post-game unlockable title screen. See the title screen expressions heading for more information.
- If the player battles Geishachi again after beating the game once, a radio can be found with a 'げきむず' speech bubble (which gives the impression that it can increase the difficulty of the boss battle) and if Starfy or Starly use a Star Spin on it, it will play an Asian shamisen version of the Title Song called Tone of Ocean Shamisen, causing her to play a bunch of notes, and making it harder for Starfy or Starly to defeat her.
- An area of Degil's Castle (9-3) has two maps with a series of blocks spelling "ハズレ" in Japanese (meaning "miss"), suggesting that the player had entered the wrong room. Four doors lead to the maps, and two lead to the correct map, with one also leading to the correct room in which the Degil's Castle song can be unlocked. This is an example of a hidden object message. A famous example of a hidden object message in another game is the the "thank you" (アリガトウ, arigatou) message in World 9-4 of Super Mario Bros.: The Lost Levels.
Sea Jams Easter eggs
- If the player chooses to play Degil's Theme 2 or Ending 2 in the Sea Jams, Starfy and Starly will wear sunglasses, the microphone will change into a pink thing apparently with a ribbon shaped part, and Mattel will turn into Lovely. These changes are reverted after the music is stopped.
- If the player touches one of the fish on the Sea Jams and nothing is overlaying the fish, Degil's laugh, the sound effect when Lovewizumi appears or the Mermaid's 'hi hi' sound effect played when saving may play.
- After a certain period of time with no tune playing, Moe will get a sweat bubble and Starfy will apparently pull a string on his violin (four lines are seen near the violin) but then pull off a disappointed face with 'empty black circle eyes'
Title screen expressions
Initial title screen
- Touching Starfy causes him to pull off a shocked expression with his eyeballs protruding, before falling down on his front side.
- Touching Moe causes him to wink with his left eye and have a star come out.
- Touching Starly once causes her to pull off a mildly annoyed looking expression, touching her again causes her to become more annoyed, turning to her right side and moving her arm, and touching her a third time causes her to clearly become angry, showing angry eyes and opening her mouth. The expressions 'loop around', so touching Starly for a fourth time causes her to pull off her first expression.
Post-game title screen
- Touching Starfy causes him to close his eyes, pull off a large grin, then spin around counter-clockwise.
- Touching Moe causes the shape of his eyes to change so they look more angry, Moe to put the two hinges of his shell together for a moment, and have a red mark appear on his face, presumably indicating anger.
- Touching Starly causes her to close her eyes, pull off a sad face, move her face down slightly and apparently hold her breath, as her cheeks are enlarged. Touching Starly for a second time does not make her pull off a second expression.
- The back of the Old Man Lobber Shirt in the Stuff has writing on it which says "I [red fork icon] ROB". ROB is presumably a reference to Old Man Lobber's Japanese name, Rob-jisan (Japanese: ラブじいさん).
- When the player starts up the game on their birthday, after the Nintendo and Mobiclip screens a 'happy birthday' screen will appear and a fanfare will play. Confetti will fall from the screen. The screen features Starfy, Moe and Starly near a cake with a board on top of it that says "Happy Birthday!" (Japanese: たんじょうびおめでとう). The cake is on a plate and has six candles. It is topped with upside down strawberries and a Starfy decoration. The player has to press A to continue.
- In the Sea Jams, when Wireless Options or The Squirts' Drums is played, Moe is replaced with Herman and Starfy and Starly will play with guitars instead of maracas (Starly) and drums (Starfy).
- In the Sea Jams, fish can be moved around by touching them on the Touch Screen and flicked by letting go off them.
- When a tune is playing in the Sea Jams, musical notes will appear. If the player uses the stylus to throw fish from the bottom screen on to the musical notes, the first part of the series Title Song will play. This can be done three more times in succession to play extra parts of the song.
- The Legendary Starfy features quizzes from Moe's siblings. They can be accessed after clearing and revisiting particular areas, and reveal secrets about the game.
- Similar to the quizzes are hidden stories told by Pufftop Guards and Starly at Pufftop which reference all previous games from the The Legendary Starfy series. These are known as The Pufftop Legends.
- List of cameos.
- List of glitches in the Game Boy Advance games.
- List of glitches in the Nintendo DS games.