land-shark (n.)

"person who cheats or robs sailors ashore," 1769, from land (n.) + shark (n.). Smyth ("Sailor's Word-book," 1867) lists the types as "Crimps, pettifogging attorneys, slopmongers, and the canaille infesting the slums of seaport towns." As "land-grabber, speculator in real estate" from 1839. In both senses often in Australian and New Zealand publications during 19c.