CURATOR COMMENT-The upgraded card's text should state 'Big Bubble' instead of just 'Bubble', to ensure it's not confused with the other card:
(i.e. - "Big Bubble has a 50% chance of bursting (dying) every turn. If Big Bubble dies, 3
are produced.")
...if there was only a bubble machine...
The quanta gain isn't as exciting as it should be, but the idea seems plausible enough as a minor critter (similar to Damselfly or Ray of Light). It's a pity that the death of the bubble allows you to reap its true benefit, but with cards like Fractal, having it die would be a great strategy as a whole.