Jellyfish
A digit that lines up in equally many rows and columns is removed where they do not meet.
All candidates have been entered in the empty cells.
In each row in A, candidate digit 1 appears only in the 4 columns in B. Because the 4 instances of digit 1 in the 4 rows in A cannot occupy the same column, one is in each of the 4 columns in B. Therefore, remove candidate digit 1 marked × in the 4 columns in B.