On the 1st day of Christmas, James Potter gave to me,
A barn owl in the beech tree.

On the 2nd day of Christmas, James Potter gave to me,
2 black eyes, and a barn owl in the beech tree.

On the 3rd day of Christmas, James Potter gave to me,
3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 4th day of Christmas, James Potter gave to me,
4 prankers pranking (stupid Marauders), 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 5th day of Christmas, James Potter gave to me,
5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 6th day of Christmas, James Potter gave to me,
6 concealed love potions, 5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 7th day of Christmas, James Potter gave to me,
7 Quidditch players flying, 6 concealed love potions, 5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 8th day of Christmas, James Potter gave to me,
8 shouting matches, 7 Quidditch players flying, 6 concealed love potions, 5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 9th day of Christmas, James Potter gave to me,
9 professors shouting, (What in Merlin's name did you do this time James?)

On the 10th day of Christmas, James Potter gave to me,
10 flying fairies, 9 professors shouting, 8 shouting matches, 7 Quidditch players flying, 6 concealed love potions, 5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 11th day of Christmas, James Potter gave to me,
11 Chocolate Frog Card... wrappers, 10 flying fairies, 9 professors shouting, 8 shouting matches, 7 Quidditch players flying, 6 concealed love potins, 5 Fanged Frisbees, 4 pranksters pranking, 3 dung bombs, 2 black eyes, and a barn owl in the beech tree.

On the 12th day of Christmas, James Potter gave to me,
12 bright red roses...

Well, he may still be a prat, but I gotta love him.