Additional control over movement behavior would be nice.
Examples:
1) A distinct spawn point separate from movement center point (e.g. mob spawns at A, moves to B, then starts random movement). Some examples: birds spawning at very high Z points and then flying down into place before pathing, undead/earth elementals spawning below ground and moving up, spiders spawning from within webs, whelpings spawning at nests, kobolds spawning at unreached nooks in a cave, etc.
2) A specified swim speed (rather than simply half movement speed). This would allow certain mobs to realistically swim faster than they walk (crocs, threshers, etc)
3) A defined "roost" point where a mob periodically moves to and performs an optional emote for a specified time (ex: wyverns/birds/dragons periodically roosting on a nest, carrion birds periodically returning to a skeleton, dryads periodically going to a moonwell, etc)