This jellyfish in a bottle looks just like the real thing! This ocean craft is easy and inexpensive to make, and it's also a fun discovery or sensory bottle. Make a jellyfish from a plastic bag and place it in a bottle of water to watch it swirl and 'swim' around! It's really mesmerizing to watch, and it makes a great prop for storytime or a lesson at school. This post contains affiliate links. If you use these links to buy something we may earn a small commission which helps us run this website. How to Make a Jellyfish in