Goliath is funny because in any other story he'd be a perfectly legitimate antagonist - he's a giant beast with horns and a mouth on his belly that can spit fireballs.
But in Devil May Cry 5, he's the first real boss of the game, who's only present to introduce the macguffin of the game - the Qliphoth fruit.
And the guy he loses to isn't even the "legendary" devil hunter - he's defeated by Nero who, at that point, had previously lost his demonic power.
Goliath boasts about his power, and Nero's never heard of him. Goliath shows off his fireball spit, and Nero calls it a "cool trick". Goliath declares his goal of claiming the fruit and becoming a king, and Nero calls him a "knuckle-scrapping fart in the wind."
Goliath calls Nero a "mere human". Nero calls Goliath a "mere demon".
In any other story Goliath would be a threat, but in Devil May Cry he's a complete loser.
