Tzatziki is a greek dish (dip) and it can have from moderate to lots of garlic, here is the recipe (I just saw it on the Food Network).
In a mixing bowl, blend
1 cup strained plain yogurt (or Greek or Balkan yogourt from the store).
1 medium cucumber very finely grated and dehydrated by putting in strainer and pressing with paper towel, (you don't want the cucumber to be watery or the tzatziki won't turn out as planned).
2 garlic cloves very finely grated (or more),
1/4 tsp onion powder,
1 tbsp olive oil, and
The juice of half a lemon.
Blend until the mix is really smooth.
It is meant to be a dip for pitas. You can keep it in the fridge for a week or so.