It's seal.cafe. They're well-known for such things.
It's not just that user, it's the entire instance that can be tossed into the sea.
https://seirdy.one/posts/2023/05/02/fediverse-blocklists/#receipts
^^^^ transphobia, racism, antisemitism, suicide-baiting, all in the receipts.
Plus: They host a bot that harasses people who post in mutual aid hashtags. (https://seal.cafe/@mutualshame)