Minecraft wiki entry for Development_versions, associated text: The Lion Tamer achievement's description has now been changed from 'Tame an Ocelot' into 'Gain the trust of an Ocelot' due to ocelots no longer being able to turn into cats by feeding them fish. Now to unlock this achievement the player must feed fish to an ocelot until it trusts them, which is indicated by the ocelot emitting heart particles.