In it's debut appearance of The Lost Lapras, Originally it was found washed up on a beach but Ash managed to help nurse it back to health until it was kidnapped by Team Rocket. Ash managed to free it and captured it until they could find Lapras' family. Lapras was primarily used as the gang's transport throughout the Orange Islands, but it was also used in several of the Gym battles and the final League match.
In the Viva Las Lapras, Lapras finally reunites with its family as its leader is mad at Ash because they are afraid of humans. After saving its mother and defeating Captain Crook and Team Rocket, Ash eventually let it go to be with its family.
In Johto from the episode, Lapras of Luxury, Lapras who is now grown and reunited with Ash who briefly haven't recognized his own Lapras when it was little. By the time they play together with Ash and Pikachu, Team Rocket captures a school of Lapras including its mother and it escapes beneath the ocean. Lapras tries to follow it as the yellow submarine manned by Ash, Misty, Brock and Naomi to follow it. Lapras was happy to see them safe but two others are missing and they are trapped in a twisted whirlpools. Lapras commands with the other Lapras by singing its travel song to find the other two and it revealed that the two other Lapras are in the shore along with Team Rocket. Lapras along with the school of Lapras manages to freeze Team Rocket's Pokémon with their Ice Beams which allows Pikachu to blast Team Rocket off. Later, Lapras became the new leader of the school of Lapras before parting ways with Ash as the latter waves goodbye to his old Pokémon once more.