Henagan, Galloping Gears

{b}: Henagan, Galloping Gears gains trample.
{1}{b}: Henagan, Galloping Gears gets +1/+1 till
the end of turn.
{1}{b}{b}: Till the end of turn, Henagan,
Galloping Gears gains "the next time this
creature deals combat damage, draw 2 cards and discard a card."