While some argue aggressive players can be the most annoying at the table, you have to give them credit. The aggressive poker player will either win the tournament or get eliminated quickly in a blaze of glory before getting into his or her stride.
If you play in enough freeroll tournaments and pay attention to your opponents' style of play you will more than likely find at least one player that falls into this category. An aggressive player sitting at your table intends to take home the money or doesn't plan to stick around and waste much time "losing". This sort of play can certainly speed things along for the table because he or she can raise and re-raise while simultaneously taking out a few players along the way.
This player is the one who will let you know while he is chatting away what he is doing so if you are playing the freeroll to win, pay close attention to what he's saying and to which starting hands he raises before the flop.
You will probably come to the conclusion that these players are those who only raise pre-flop with the top 10 starting hands. Even though they seem to be in a hurry to win it all or they don't want to stick around very long, don't forget they are "in it to win it" and prefer to win the tournament outright than merely be "in the money".
Even though you may not regard the aggressive player as a worthy opponent then make sure you understand the following points. If the stakes are low the opposite may in fact be true. Why would a good player want to play four or five hours of poker in a large freeroll when the most money they can walk away with is a share of $15?
If, however, the stakes are much higher and it's a $10,000 freeroll for instance, watch for the guy who gets in a hurry. You need to keep him quiet and out of as many pots as possible if he's a big bluff. His bluffing may earn him a share of some sizeable pots.
Remember, if you don't slow down an aggressive player who bluffs his way into some large pots, they can be dangerous when they lose the roll of "bluff" and take over the roll of "bully" with a stack of chips at their disposal.