Talk:Far Harad Jungle/@comment-24071602-20160111230536/@comment-25101089-20160718160551

Because they have buggy spawning mechanics. Mojang added them to the 'monster' spawn list, so they can constantly despawn and respawn as opposed to spawning at world gen like other animals, but Mojang didn't code them as the 'monster' type and thus they don't count towards the spawn cap of their own list. This means that Ocelots will spawn indefinitely and given enough time (if the player is standing still) will wreck the world's tickrate and FPS.

If they were made to spawn at worldgen this issue would be fixed. But they despawn when untamed, so any Ocelots spawned at worldgen would quickly disappear, and not respawn.