The Old Man debuts in the original The Legend of Zelda, where he is in a cave, after Link enters the cave. The Old Man has his very iconic lines "It's dangerous to go alone, take this", which he has a sword, that Link can take. He disappears once Link takes the sword. He appears a lot more in the game as a recurring character.
Role In Abobo's Big Adventure
Unlike his original counterpart, The Old Man is a antagonist in Abobo's Big Adventure, a merchant in the Zeldabobo dungeon mentions "the Old Man hates beef". Later you can get a beef power-up from an underground segment, and use it to defeat the Old Man.
Once Abobo walks in, the Old Man powers up with a shield, and you have to defeat his beams. After you defeat the Old Man, you spin his head by the effect "meat spin", into the wall creating a crash. You can get either two medals if you beat him with a sword or the beef power-up, after his defeat, you can now recuse Princess Zelda and head to the start of Pro Wrabobo.
The Old Man starts off with a shield, and he kicks the fight off by spawning enemies from his book you've fought earlier in the stage such as Choco Kisses, Octoroks, Skeletons, Tektikes, Bob-ombs, Shy Guys, Ghosts and Flurries. He can send out a wand that summons a yellow homing projectile which, if you get hit by it, you will be turned into a snail for about ten seconds, and will be more prone to being attacked. He can fire red lasers from a small ring, and a homing stream of fireballs from a candle. Then, after taking enough damage, he splits himself into three more old men, who can use a spin attack using a sword, then, he drinks a potion, transforming into the Old Giant, he can hit like a tank but he's a much larger target and his attacks are easier to dodge, but he gains invincibility frames during his attack start up, and causes rocks to fall down on flashing red and white X's.