kotobuki_(tiny_life)
Artist. The author of original manga series Atarimae WonderWorld.
Japanese name: 寿 (Kotobuki)
The other name: "buki"
Circle & site name: TINY LIFE (タイニーライフ)
According to other twitter followers, his Kemono Friends 3 account is still in frequent use, but the reasons for why s/he left the art scene are unknown.