There Was a King in CoS-HBP revealed!

[quigonginger]

No: HPFGUIDX 103642

In our quest to find the prince, we seem to have overlooked the 
King.  The basilisk is the King of Serpents.  We also know, both from 
FB and from the page found in Hermione's petrified hand, that the 
basilisk is made by hatching a chicken's egg under a toad. 

A half-blood basilisk would be either a chicken (male-rooster) or a 
toad.  We know the roosters were all strangled, so that leaves....

Drum Roll, please...

Yes, Trevor is the HBP.

Thank you.  Hold down the applause, please, you'll wake the 
neighbours.

Ginger, noting that with Arthur's schedule of blood replacement 
potions in OoP, he could well have been half-blooded at that time.