Comment by arcane_node

Exactly what oakwhiz said. Similarly, if you set all 256 bits of the entropy portion to 1 (i.e. you play minesweeper with my grid) then the resulting valid mnemonic is zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo vote. The last word contains the checksum, which is the hash of the string of 1s.