You jest, but cybernetic implants to remote control cockroaches and flying beetles is a thing, and even normal people can buy the former (RoboRoach Bundle is about US$160), so I wouldn’t be very surprised if someone makes a crab-based delivery cyborg.
Neural interfacing is not that complicated. It's just a microcontroller with two of the GPIO pins connected to antenna nerves, at most $5 worth of hardware.