Parrots imitate mobs with multiple idle sounds incorrectly. So far this affects:

• Guardians (always imitate underwater sounds even when the guardian is flopping around on land) (before 17w17a)
• Guardians and Elder Guardians (always imitate out-of-water sounds even when the guardian is underwater)
• Tiny slimes and magma cubes (imitate large slimes/magma cubes instead of tiny ones)
• Endermen and wolves (do not imitate angry sounds when the mobs are aggravated)

Some of this is probably me being nitpicky, but they should at least be consistent with the guardian/elder guardian sounds.