Appears as part of the Ranger version of the Epic Ornamentation task, "An Epic Request" (see this quest entry for details).
Each time the task is run, the location of the tracking sub-components changes (apparently randomly). There is no specific spot Hopkit shows up - he appears after you have successfully snared "a distressed aviak."
If you attempt to speak to Hopkit, you will receive this message:
Hopkit snarls at you angrily, 'This evil it must be you!' Perhaps you should find a way to calm him so you two can converse...
You need to cast a lulling spell (such as one from the Veil line) on him. When you do that, you'll receive the message:
Hopkit looks far more reasonable now, try talking to him again!
When you hail him again, The Vessel of Hate spawns and Hopkit becomes aggressive. A screen message will come up five seconds later saying:
A motherly voice calls out to you, 'Please do not harm Hopkit. Find a way to CURE him of his affliction...'
You need to cast balming spells on him. You will need to do this three times. The first time, his appearance changes to an undead rabbit look. The second time, his appearance changes to a comical polka-dotted "Wonderbread" look, and the third time will finish curing him. You will then see:
Hopkit says 'Thank you my friend! I fear our friend Beyar may have been afflicted worse than any of us! Please, find him and do what you can...'
Hopkit then despawns, and the next tracking target ("fresh prints") will appear.