user16626: In Queen's Gambit Declined, Albin counter-gambit, Lasker trap, black ended up with three knights, which should be rare. Here white should not capture the additional knight in the next move (8. Rxg1 Bg4+ and black is winning). Are there any other openings that one side ends up with three or more knights?
[FEN ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. e3 Bb4 5. Bd2 dxe3 6. Bxb4 exf2 7. Ke2 fxg1=N


user18168: As @JossieCalderon pointed out, any opening could end up with three knights for one side. This would always require a knight promotion of some sort. Usually, knight promotions occur to

Give check to the opponent immediately to move the king to another square or to save a tempo.
Avoid a knight fork from the opponent, or give one of your own
Avoid stalemate
Give checkmate

I think, however, that you are also asking if there is another opening where knight promotion occurs in the opening phase of the game. The answer is  most likely "no".

16626: <p>In Queen's Gambit Declined, Albin counter-gambit, Lasker trap, black ended up with three knights, which should be rare. Here white should not capture the additional knight in the next move (8. Rxg1 Bg4+ and black is winning). Are there any other openings that one side ends up with three or more knights?</p>

<pre><code>[FEN ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. e3 Bb4 5. Bd2 dxe3 6. Bxb4 exf2 7. Ke2 fxg1=N
</code></pre>  
 18168: <p>As @JossieCalderon pointed out, any opening could end up with three knights for one side. This would always require a knight promotion of some sort. Usually, knight promotions occur to</p>

<ol>
<li><p>Give check to the opponent immediately to move the king to another square or to save a tempo.</p></li>
<li><p>Avoid a knight fork from the opponent, or give one of your own</p></li>
<li><p>Avoid stalemate</p></li>
<li><p>Give checkmate</p></li>
</ol>

<p>I think, however, that you are also asking if there is another opening where knight promotion occurs <em>in the opening phase of the game</em>. The answer is  most likely "<strong><em>no</em></strong>".</p>
