this definitely lacks in the sense-making...

On the twelfth day of Christmas, feikoi sent to me...
Twelve dragon_changs drumming
Eleven celinafairys piping
Ten colossus a-leaping
Nine crossovers dancing
Eight androgynous a-milking
Seven btvs a-swimming
Six comics a-laying
Five acti-i-i-ion flicks
Four young avengers
Three comic books
Two teen titans
...and an apollo in a buffy.
Get your own Twelve Days:

(they just looked for things that ended in 's', didn't they...)

...Though it does spawn plot bunnies. Authority/Buffy crossover?