Minecraft wiki entry for Nether_portal, associated text: Most entities can travel through portals, including mobs (except the wither and ender dragon), thrown items, and transportation without passengers (neither mobs nor player)[1], including boats, minecarts and horses. Unlike players, other entities travel through portals instantly, and once they reach the other side, there is a cool-down time for 300 game ticks (15 seconds), in which they cannot go through any nether portals. Therefore, an entity can only travel though nether portals again, once it is not touching any nether portal for 15 seconds. In Bedrock Edition, a parrot on the player's shoulder prevents the player from going through the portal.[2]