Could there be a colonial organism (hydrozoa, siphonophore, etc.) Consisting of vertebrates of any size exist?

Could there be a colonial organism (hydrozoa, siphonophore, etc.) Consisting of vertebrates of any size that act like 'zooids,' exist?

I have never seen something like that; colonial vertebrates I have seen are just their own individual organisms.

I could see this being fictitious, but I'm just curious if it is possible or if there actually is a species of vertebrate like this.