Hydrozoa

Many of you tiny cnidarians band together, to form what appears to be a single organism.  You are mostly, even in a group, quite tiny, but a few of you form colonies which are up to a couple of metres across.

Interestingly, many of your forms are not just a group acting together, but actually acting as a single organism, with the internal cavities joining into those of other individuals, in a conjoined form.

A few of you have given up on the 'normal' jellyfish form and spend only a tiny part of your life like that, having expanded the proportion of the larval stage to almost all of the time.  Medusa are single individuals which join to others and grow to form colonies.  As a result, only the single organisms can swim effectively and the colonies are either anchored to the sea bed, like fire corals, or floating freely with the wind to drive them, like Portugese Man o' War.

Some of you have adapted to form symbiotic relationships with crabs, and eat the crabs scraps in return for providing a stinging defence.  A few of you have even adapted to live in fresh water.

That's as far as you can evolve here!  
You can go back to the start with the link above, or share what you became with the icons below.