After switching my server to Peaceful mode, my players began to complain about large numbers of ocelots spawning in the jungles. The ocelots began lagging the server severely, at which point I took the server down and restored from a backup made before this problem began. The problem, nevertheless, persisted - ocelots began spawning in all jungle biomes, with no apparent end.

I then created a new world (using the same seed), and this behavior persisted - ocelots spawned in peaceful mode in large numbers.

When I attempted to reproduce this bug on a single-player world, I was unsuccessful.