Subtle (Harry Potter rec)

I find that there's a theme to my recommendations where I write, "Yes there are dozens of similar stories but this is the best because...."

In that vein I am recommending Resonant's The Familiar. Harry gets turned into some type of animal and then bonds with Snape is a premise that has been done before, but this story is remarkable for its pacing and the subtleness with which the story is told. She doesn't over-explain or over-describe, but instead sketches the outlines of a picture and lets the reader fill in the blanks.

The Familiar by Resonant
Snape/Harry Slash
http://trickster.org/res/familiar.html