I don't know how everybody calls it, but I call it the broken phone:
Someone says 1 word (me, in this case) then the next person says another word which can be used together with the first word to form a sentence.. the 3rd person must repeat all words and add another one; like this:
1. Cat
2. Cat goes
3. Cat goes up
4. Cat goes up the
5. Cat goes up the tree
...etc...
I start: INHUMAN