—Sharktronic Sand Sub's splash screen
Sharktronic Sand Sub is a Beach zombie introduced in Plants vs. Zombies 3. It appears identical to a Shark Costume Zombie until it is revealed and cannot be damaged until it attacks. Sharktronic Sand Subs can appear in the Beach Trick "Feeding Frenzy", along with Shark Costume Zombies.
Its ability to dig underground is based on the Zombot Sharktronic Sub's ability to dive underwater in the second game.
Sharktronic Sand Sub is quite dangerous as it avoids plants until it attacks and has a good amount of armor to withstand damage. Using Buttercup can stun it and give the player a better chance at defeating it; when it has surfaced, Kernel-Pult and Butternut Squash can also stun it. Puff-Shroom can be used to make it surface farther from plants, allowing Sharktronic Sand Sub to be damaged more before it reaches the frontline.
- Unlike his Plants vs. Zombies 2 and Plants vs. Zombies Heroes counterparts, it now has a red antenna instead of yellow.