Rick was building a soapbox racer with his grandson Morty in the garage when he started to goof around a little with a water hose. As he laid down the hose he expressed how he appreciated spending time with his grandson Morty, but was interrupted when a green goo monster appeared in front of their house. Rick immediately knew it was coming for him and threw his portal gun to his grandson just before being impaled by the monster. With his last words, he told to his grandson to warn the other Ricks that "it's starting", before the monster killed him.
This version of Rick seems to be very fond toward his grandson Morty a lot more than what's common among Ricks. He told his grandson how he had fun spending the day with him and building the soapbox racer; and when faced with imminent death, he handed his grandson Morty his portal gun instead of attempting to escape himself.