在《合金彈頭》（メタルスラッグ/台:越南大戰）系列遊戲中，有一位打不死的小強角色名叫艾倫。他是一個光頭小頭目，除了在第5和第6代未出現外，從第1代到第7代都有登場。首次出現在第1代的第3關，是摩登最忠誠的軍官之一，從摩登還未叛變時就與他一同出生入死。當艾倫在第1代被擊敗時，其實他並沒有真正死亡。在第2代，又再次出現，被打倒後掉入水中，疑似被鯨魚吞下，接著水面上漂浮著數根骨頭。然而，真相是當他被鯨魚吞下時，回想起最近收到妻子的家書，得知兒子已經出生。於是他用盡最後的力氣在鯨魚的肚子上打出一個大洞後逃出。遊戲畫面中出現的骨頭其實是鯨魚的。

在《合金彈頭3》的最後關卡中，艾倫又再次現身於直升機中。當他被擊敗後，會短暫地與玩家並肩作戰，共同對抗火星人。他的目的是救出被火星人抓走的摩登。在《合金彈頭4》中，艾倫出現兩次，分別在第2關的碉堡塔和最後關卡。消滅他後，會發現這其實是一個機器人。艾倫在第5代和第6代中沒有登場，直到第7代的第6關又再次出現。

In the Metal Slug series, there is an indestructible character named Allen O’Neil. He is a bald-headed mid-boss who appears in every installment from the first to the seventh, except for the fifth and sixth games. He first appears in the third mission of the first game as one of Morden's most loyal officers, fighting alongside him even before Morden's defection. When Allen is defeated in the first game, he does not actually die. He reappears in the second game, where, after being defeated, he falls into the water and is seemingly swallowed by a whale, with a few bones floating to the surface. However, the truth is that after being swallowed by the whale, Allen recalls a recent letter from his wife informing him of the birth of their son. He then uses his last bit of strength to shoot a hole in the whale's stomach and escape. The bones seen in the game are actually those of the whale.

In the final mission of Metal Slug 3, Allen reappears in a helicopter. After being defeated, he temporarily fights alongside the player against the Martians. His goal is to rescue Morden, who has been captured by the Martians. In Metal Slug 4, Allen appears twice: once in the bunker tower in mission 2 and again in the final mission. Upon defeating him, it is revealed that he is actually a robot. Allen does not appear in the fifth and sixth installments, but he reappears in the sixth mission of Metal Slug 7.

照片:產品官網