Lobster – either a soldier (red uniform) or a policeman (dark blue like an unboiled lobster).
This is also quite a Liverpool-y kind of page. There’s “lobscouse”, the local speciality dish of Liverpool still, although now just it’s just called scouse (of course). The old recipe differed a bit with the inclusion of “biscuit”, which as befits a port city, means ship’s biscuit, hard tack, made only from flour and water.
This was long before Liverpool’s love of scouse resulted in its people being known as scousers, which didn’t enter the lexicon until around the Second World War. I’ve previously posted about one Victorian nickname – Dickey Sam https://skittishlibrary.co.uk/we-are-the-dickeymen/. Here is (almost) the much better known one – “Liverpudlin”. But I can’t now find any reference to this particular spelling outside this book.
Going back to Lobsters for a minute, have a vardo at this Horrible Histories sketch that mentions this slang and much more: