There's a healing item in Undertale called dog salad which heals a random amount of HP between 1 and 20. During a boss fight in Joe's Undertale playthrough, he used the dog salad to heal, and it healed him by 2 HP, so he said "curse you, dog salad".[1] He still says "fucking dog salad" sometimes when something in a game doesn't help him much.

References

  1.     “Joseph Anderson Channel Two” video: “Undertale Third Run (Genocide - Still Blind)” at 03:48:56.