Should be possible. Whatsapps requirements for Stickers are that they must be 512 x 512 pixels and at most 100 kB, i don’t have the exact pack but i do have one from the same artist and all from that one do fit those requirements. Even if not resizing them for that is possible.

Seems to be from this one: https://www.pulexart.com/store/p32/Wolf-stickers-2.html

They probably meant “anchor point”. Maybe they also speak german (Anker is german for anchor) and confused the spellings between the languages.

Here is the source: https://www.tumblr.com/ask-crow-aus/759912849861754880/slytherin-assassin-lattemonstr-aishishiii . It is one reblog further down, as slytherin-assassin deactivated their blog and lattemonstr apparently has no post on their blog, probably deleted when they moved on to a different blog.