'Twas Brilig is a short song featured in the 1951 Disney feature film, Alice in Wonderland, it is sung by the Cheshire Cat. The song's lyrics are actually the first stanza of the Jabberwocky poem by Lewis Carroll, from the book Through the Looking-Glass (an early rendition of Alice in Wonderland).
And the slithy toves
Did gyre and gimble in the wabe,
All mimsy were the borogoves
And the mome raths outgrabe.