Similarly, in the cultural realm, we have cultural creatures with memotypes.
Genes and memes are units of selection. Creatures are the target of selection. They are what natural selection chooses between.
Organic creatures involve groups of genes that die at the same time and (mostly) reproduce at the same time. Similarly cultural creatures involve groups of memes that die at the same time and (mostly) reproduce at the same time.
We can see cultural creatures in many places. One example is on peer to peer networks. Audio and video files are examples.
In the organic realm there are composite creatures - such as the Portugese man-o-war - which are individuals that are composed of multiple other individuals. Similarly, there are composite creatures in the cultural realm - so, for example, there are albums that are composed of multiple different songs - and both the albums and songs would qualify as being cultural creatures.
Few of those in the field with an academic background seem to understand the existence of cultural creatures. I have described this omission in another article: Why no cultural creatures in academia?
There's another article where I go into definitions of the term "organism" in more detail: Cultural organisms.