Green’s Dictionary of Slang

crawler n.

1. [mid-19C+] a general insult.

2. [late 19C] (Aus.) a shepherd, a musterer; one who mends boundary fences.

3. [late 19C+] (Aus.) a slow-moving, unexcitable domestic animal, esp. a sheep.

4. [1920s+] (US) a legless beggar, usu. moving with the aid of a small wheeled platform.