Answer:
Microparasite expert at sucking the blood of mammals and birds
My first is twice in apple but not once in tart. My second is in liver but not in heart. My third is in giant and also in ghost. Whole I'm best when I am toast.
I have a shell and move very slowly but I don't live in the sea. What am I?
What do pandas have that no other animal has?
This small creature kills even the largest one.
I hold two meanings. With one I may be broken, with the other I hold on. What am I?