Neville Longbottom

Bravery: As long as you control at least two
Students and/or Teachers, Neville Longbottom
gets vigilance and +1/+1.
{2}{g/w}{g/w}: Grow up 4. (If this creature isn't grown up,
put 4 +1/+1 counters on it and it becomes grown up.)
As long as Neville Longbottom is grown up, he
gets first strike.
"I'll join you when hell freezes over!"