A lot of pests can’t stand the smell of garlic, with examples including aphids, armyworms, beetles, caterpillars, cutworms, mites, mosquitoes, and some types of fly (excepting onion flies, however, who will happily lay eggs in your garlic). If you have some plants that could make use of these qualities, then you might just have a potential companion plant for your garlic that will do very well with it nearby.