Okay, I've been going crazy searching for this fic.
I believe harry was rescued from the Dursleys at at young age and
goes to live with Severus. One day (before he lives with Snape), Harry recieves an egg from a
creature. When Severus finds it, he fears that the egg might be that of a poisonous or dangerous
creature. He worries that the thing will harm Harry when hatched and throws the egg into the fireplace.
Harry gets very upset and retrieves the egg from the fire...or ashes. Later, Albus and Sev find out that the egg will hatch to be Harry's
familiar. Seveurs apologizes to Harry for taking away his familiar...probably the only one he will ever find. Severus is very upset over this because he never found his own familiar.
Harry holds the egg close and tells Severus that the egg is not harmed.
I really hope someone knows the fic I'm talking about...
FOUND:
Are you my Daddy?