Artist.
Japanese name: 大山 ますたんぐ (danbooru's Romanization: Ooyama Masutangu)
The other name: ススキ (Susuki)
https://twitter.com/masutang_
https://twitter.com/intent/user?user_id=588015484
https://www.tinami.com/creator/profile/36798
https://www.pixiv.net/users/3867909
https://www.pixiv.net/users/4462449
https://www.pixiv.net/stacc/119219791017
https://www.pixiv.net/stacc/masutang