When Plankton insults Taylor in "20,000 Patties Under the Sea," his ex-wife takes offense and says, "Hey, you can't talk to my son that way," so Plankton fires back at her. Then he comes out and says, "You can't talk about my wife that way! What do you think this is?" When Plankton calls him fat, his mother comes out in his defense, and Plankton tells her that she belongs in a box floating down the river, and she replies, "You're probably right."
When Plankton turns to leave, the truck driver and his family begin to throw rocks at him and his submarine (the fist on the Chum Bucket). When they run out, SpongeBob and Patrick sell them Krabby Patties that Patrick left unattended, therefore burned, in their sub (the one they found by their houses).
It was unknown if he died or got severely injured when his truck hit Squidward's house and exploded in "Squid Baby" although it is revealed he didn't since he appeared in the later episode "Food Con Castaways."