Stage 1: Create the Player Fish
Keep your Scratch project tab open all week. Open in a new tab so you don’t leave the course.
a fish sprite with two costumes and two sounds
how one sprite can have many looks and a voice
the Player Fish, ready to move in Stage 2
Before campers touch their laptops, show the whole room:
- Open your saved Scratch project. Click on Scratch Cat in the sprite pane.
- Click the Costumes tab. Show the cat's two costumes.
- Click Choose a Costume and pick Fish-a from the Animals category. Then Party Hat-a from the Fashions category.
- Delete the two cat costumes by clicking the × on each one. Only Fish-a and Party Hat-a remain.
- Click the Sounds tab. Add Bubbles and Eggs.
- Rename the sprite to Player in the sprite pane.
That whole demo takes about 90 seconds. Campers will do the same thing.
The big idea
Every game has a main character. In Fish Food, that character is the Player Fish — the fish you control with the arrow keys, the one that eats smaller fish and tries to avoid bigger ones.
Today we don't write any code. We give the main character a body and a voice.
In Scratch, a sprite is any character or object on the stage. A sprite can have many costumes — different looks the sprite can wear. A sprite can also have many sounds — short audio clips the sprite can play.
Our Player Fish gets two costumes because the game tells two different stories. Most of the time, the fish is just being a fish (the Fish-a costume). When the player wins, the fish puts on a party hat (the Party Hat-a costume) to celebrate. Same sprite, two looks.
The fish also gets two sounds: Bubbles (sad, plays when the fish gets eaten) and Eggs (a celebration sound, plays when the fish wins). Sound is feedback — the player hears what just happened.
- sprite
- a character or object on the stage
- costume
- one of the looks a sprite can wear
- sound
- an audio clip a sprite can play
- sprite pane
- the list of all sprites, at the bottom-right of the editor
- Costumes tab
- the tab at the top of the editor where you change a sprite's costumes
- Sounds tab
- the tab at the top of the editor where you add sounds to a sprite
Your Scratch project from Setup should be open — Fish Food — First Last. It should still have the Scratch Cat sprite as Sprite1.
Build it
Step 1 — Open the Costumes tab
We start with Scratch Cat (the default sprite). We're going to swap its looks out — but we keep the same sprite. (Step 6 we'll rename it to Player.)
In the sprite pane (bottom-right), click Sprite1 (the Scratch Cat).
At the top of the editor, click the Costumes tab. You'll see two costumes — costume1 and costume2. Those are the two cat poses.
Step 2 — Add the Fish-a costume
Now we add a new costume from Scratch's costume library.
At the bottom-left of the costumes panel, hover over the cat-face icon. A menu pops up. Click Choose a Costume.
A library opens. Click Animals in the categories at the top. Find Fish-a (a clownfish — orange and white stripes). Click it.
The Fish-a costume is added to your sprite. You should now see three costumes in the list: costume1, costume2, and fish-a.
Step 3 — Add the Party Hat-a costume
Repeat Step 2, but pick a different costume this time. We need a "winning" look for the fish.
Click Choose a Costume again. This time click the Fashions category. Find Party Hat-a (a party hat). Click it.
Now you have four costumes: costume1, costume2, fish-a, and party hat-a.
Step 4 — Delete the two Scratch Cat costumes
We don't need the cat anymore. Time to clean up.
In the costumes list (left side of the panel), find costume1. Click the small × in its top-right corner. The costume disappears.
Do the same with costume2.
You should now have only two costumes left: fish-a and party hat-a. That's the Player Fish.
Step 5 — Add the Bubbles and Eggs sounds
Click the Sounds tab at the top of the editor.
You'll see one sound already there — Meow (the cat's sound). We don't need it, but we don't have to delete it. We'll just add two new ones.
At the bottom-left of the sounds panel, hover over the speaker icon. Click Choose a Sound.
A library opens. Find Bubbles (a bubbling/popping sound). Click it.
Click Choose a Sound again. Find Eggs (a cracking/celebration sound). Click it.
You should now see at least three sounds in the list, including Bubbles and Eggs.
Step 6 — Rename the sprite to Player
In the sprite pane (bottom-right), click on Sprite1 to make sure it's selected. Look above the sprite list — there's a text field that says "Sprite1."
Click on that text field and change the name to:
Player
Press Enter. The sprite is now called Player. You can see the new name in the sprite list.
Save your project (File → Save Now).
Understand it
The Player Fish is one sprite with two faces. Both costumes belong to the same sprite — Scratch keeps them as a list. We pick which costume to show using a switch costume to block (which we'll use in Stages 2 and 4).
The reason we have two costumes instead of two sprites is important. If the party hat were its own separate sprite, we'd have to coordinate position, size, and rotation between it and the fish. Way more work. By making it a costume, the party hat IS the fish — it inherits all the fish's properties. One sprite that can wear a hat.
The two sounds play the same role. Bubbles sounds sad and watery — it tells the player "you got eaten." Eggs sounds bright and celebratory — it tells the player "you won!" Pros call this audio feedback: making sound match emotion. Without sound, every event in the game looks the same. With sound, the game tells the player how to feel.
We didn't write a single line of code today. That's on purpose. Setting up the sprite properly — right costumes, right sounds, right name — saves you time in every future stage. A messy sprite list breaks Stage 8 (collision detection) because the code has to look up the player by name.
Try this
Try this
Three short experiments. Predict before you run, then test your guess.
Click on the fish-a costume in the list. Now click on party hat-a. Predict — when you click between them, does the sprite on the stage change too? Try it. What does this tell you about what a costume is?
Click the Sounds tab and click the ▶ play button next to Bubbles. Then play Eggs. Which one would you want to hear when you win? Which one would you want to hear when you lose? Game designers pick sounds to match emotions.
Stage 2 makes the Player Fish move. To do that, we need to make sure each new game starts with the Fish-a costume — not the Party Hat one. Which block in Scratch could switch the costume back to Fish-a at the start of every game?
Test your stage
- Your sprite has exactly two costumes: Fish-a and Party Hat-a.
- Your sprite has at least the Bubbles and Eggs sounds in the Sounds tab.
- Your sprite is renamed to Player in the sprite pane.
- Clicking the sprite shows the Fish-a costume by default on the stage.
- Your project is saved (File → Save Now).
- Design check. Look at the sprite pane. Does the name "Player" tell you what this sprite does in the game? Good sprite names are short and meaningful.
If it breaks
- I deleted the wrong costume. Click Choose a Costume and re-add Fish-a (Animals category) or Party Hat-a (Fashions category). They're easy to find.
- I accidentally deleted both costumes. That's okay — the sprite still exists, just with no look. Use Choose a Costume to re-add Fish-a, then Party Hat-a.
- My sprite is named "Player1" or "player" or something else. Click the name field in the sprite pane and retype it as exactly Player (capital P, no number, no space).
- The Bubbles sound is missing. Check the Sounds tab. If you don't see Bubbles, click Choose a Sound and add it again.
- The party hat looks weird on top of the fish costume. That's because they're two SEPARATE costumes, not a fish-with-hat costume. We don't display both at once — Stage 4 switches between them.
The single biggest setup failure: campers who delete the WRONG costumes. They keep costume1 and costume2 (the cat poses) and end up with cat-with-fish, which looks broken. Walk the room after Step 4 and confirm every laptop shows only Fish-a and Party Hat-a.
The second most common: forgetting to rename the sprite to Player. The collision script in Stage 8 looks for a sprite literally named "Player" — if it's still "Sprite1" or "player" (lowercase), Stage 8 fails silently. Walk the room after Step 6.
The Sounds tab is unfamiliar to most kids — they default to Costumes and Code. Specifically point at the Sounds tab in Step 5. Some kids will add Bubbles and forget Eggs, or vice versa. Use the bulleted Test list to spot this before they move on.
If a camper finishes in 15 minutes, push them into the medium stretch (color the fish). The hard stretch (Fish-b for animation) is a Stage 9–10 polish move — only push it if they're way ahead.