Redshirtnpc's Comments

As of 7/16/19 this is still working. The pet shows up as a gift in collections.

As others have said, HOTS account level is the sum of your hero levels. Pick a handful of heroes and level them 2-3 times.

The mirecrawler was attached to the ceiling of the cave where you find the Hissing Chitterspine. Not easy to get to, but not hard to defeat. I'm not sure what the actual droprate is, but it dropped for me on the first kill.