The illustration of the sitting Hunter with the Threaded Cane on page 91 of Blood Echoes features an Easter egg.
The symbol of the two joined snakes is hidden between the Caryll Runes. This could be the beginning of a serial Easter egg as Soul Arts also features the hidden snakes.
The two joined snakes can also be found on the Caduceus Round Shield and they’re part of the Tune & Fairweather symbol decryption key where they represent the letter T.