Badmitton birdie bug

[dolphindan]

Hello, can someone help with identification of this. Just noticed a few swimming around and stuck to the glass. They look like badmitton birdies when then are swimming to me, hence the title lol. I’ve only ever put Tigger Pods in and I’m not sure if this is them in a different stage of life or something new. Would love the help. Thanks!

 

[Crabs McJones]

hydroid jellyfish, they tend to die out on their own