Toves are a new type of "Jabberwockian" that can be encountered in dNetHack. On every move, they have a 5% chance of digging a pit in the ground ("The tove gyres and gimbles into the ground"). If a tove digs in a square that already contains a pit, it creates a hole and falls through to the next level. Otherwise they are not tunneling creatures like rock moles. They are immune to grab and swallowing attacks.Toves are a valid polymorph form. A player polymorphed into a tove can dig with #monster, is immune to grab and swallowing attacks, and can also quickly open tins without a tin opener.
'Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe.