They’re called kaomoji, like emoji. In Japanese, emoji means “image-letters” and kaomoji means “face-letters.” The English word for them is probably emoticons, but that more refers to things like :-) and xD. Kaomoji can be called “Japanese emoticons.”
If you have an Android phone, your keyboard has built-in kaomoji ヾ( ͝° ͜ʖ͡°)ノ♪. You can access them by opening up the emoji panel at the bottom left, then tapping the “:-)” button at the bottom right, which contains some western emoticons but many categories of kaomoji
At your service ( ̄^ ̄)ゞ