'Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe ...
Full text here.
Carroll (Rev Charles Dodgson) wrote the poem for his family in their personal publication Mischmasch, as a way of showing how not to write a poem.
There's a full, updated, list of our Poems of the Week here.