counter opening.

playerbiki
How to tackle fried liver attack other than traxler?
Strangemover

4.d5 5.exd5 Na5 or b5 

kindaspongey

Also, maybe 3...Bc5.

Zugerzwang
The Traxler is not a way of responding to the Fried Liver Attack (which happens after 4 Ng5 d5 5 exd5 Nxd5 6 Nxf7 Kxf7 7 Qf3+). The Traxler Gambit (4 ... Bc5) is simply a counterattacking line against the Two Knights Defense which offers up the f7-pawn while avoiding the Fried Liver Attack. Playing 4 ... d5 5 exd5 Na5 (main line of the Two Knights Defense) or 5 ... b5 (the Ulvestad Variation) also simply avoid the Fried Liver Attack. 3 ... Bc5 is simply playing a different opening, the Giuoco Piano, which naturally also avoids the Fried Liver Attack. Contrary to some beliefs, simply playing 4 Ng5 does not constitute the Fried Liver Attack. Black has to invite it by continuing 4 ... d5 5 exd5 Nxd5. Once White sacrifices the knight with 6 Nxf7, Black doesn't have much choice except to accept it and try to avoid getting mated in the coming attack, while holding on to win with his extra material (if he doesn't give it back). Playing 5 ... Nxd5 used to be thought a beginner's mistake, but it has been shown that with perfect play Black may be able to defend the position and avoid being mated (but probably not recommended for most unless you can play like a computer).
Zugerzwang
I meant the Traxler is a counterattacking line against White in the Two Knights Defense (which of course is a Black Defense). (I don't see a way to edit from my phone)