Some origami models just sit there looking pretty. This one has a party trick: you blow it up. The balloon goldfish is a water-bomb style model, meaning the paper is folded into a sealed pocket that you inflate through a tiny gap at the end. That moment when the crumpled folds suddenly swell into a plump little goldfish never gets old — whether you're making it for a classroom craft table, a rainy-day activity, or just because it looks satisfying to build. The folding itself is surprisingly gentle: a few halves, some corner folds, and one clever tuck, with plenty of photos so you can't get lost. All you need is a square of paper and a straw. Blow slowly, watch it fill out, and try not to grin.

STEP 1.

Place the origami paper with the colored side facing up, fold it in half along the dotted line, and make a crease.

STEP 2.

Turn it over.

STEP 3.

Fold it in half along the dotted line and make a crease.

STEP 4.

Fold along the creases.

STEP 5.

Turn over one flap and fold it along the dotted line so that the corners match.

STEP 6.

Fold along the dotted line so that the corners meet in the center.

STEP 7.

Fold along the dotted line so that the corners match.

STEP 8.

Fold the corner along the dotted line and tuck the folded part into the gap.

STEP 9.

Turn it over.

STEP 10.

Fold along the dotted line.

STEP 11.

Fold along the dotted line.

STEP 12.

Stand the model up vertically.

STEP 13.

Insert the straw into the gap indicated by the arrow.

STEP 14.

Seal the rest of the gap with your finger and blow air into it.

STEP 15.

Shape the model, and your balloon goldfish is complete.