"You sense an eerie presence..."

I got this message a few hundred blocks south of the Frontier South Outpost on SMP2, so a Marlix will probably soon spawn. If you'd like to kill a Marlix for me so I don't die, that'd be great, and you'd get some drops. Post on this thread once you're there, I'm logged off out of fear.

Marlix only has 20 health you know (10 hearts)

If you log off all monsters spawned despawn unless someone else is loading the chunks. It's long gone now.

Was that implemented in a recent update? Because I had one despawn because I lost connection about a month ago.

Only 20 Hearts? >.>

10 hearts same as a player.
Edit: its also best to fight him in the rain, as water removes his ability to fly XD #revealallthesecrets

he still moves when you log so he might of just flown off

Alright

I guess that makes sense.

No longer matters, I afk'd and was dead when I returned

Wastelands SMP8, (1600,1600)

Apparently minibosses just love that peninsula.

EDIT:
And immediately after posting this, Momentus has joined the fray. D:

I noticed that too, I got double marlix within a small area, on a desert peninsula.

Just an update, they are both dead (for now).
Marlix aggro'd on me before anyone else arrived, so I had to put him down.
Thanks to kevdudeman, southpark347, B4DMAN5ION (did I forget anyone?) who helped me put Momentus out of his undead misery.

Choongjae for being the fish.
*blub blub*

I'm out in smp4 wastes and I just got this message a little north east of NE Outpost... I'm boxed in underground haha

though they are not 'meant' to despawn, there are still instances where marlix will despawn for unknown reason. In my experience: When you get close enough to marlix for him to target you, he will either attack or despawn. I've not figured out why he despawns.

Also, on a side note:
Enraged will despawn if the chunk is unloaded. they will not despawn while loaded however. 'Normal' mobs will eventually despawn if left loaded but not targetting a player.
Mini-bosses will not despawn for a very long time (do they ever?). Even if the chunk is unloaded, they will still be there when the chunk reloads. Marlix especially can travel a very long way very quickly though, and often leaves your visual range in a short amount of time, so can seem like he despawned.

This, also from what I've seen marlix sinks like a stone in water so you can sometimes lose him in rivers and lakes

I think that happened to me as well while exploring to find a good spot for an outpost... I was cowering in a tiny cobblestone house and when I came out there was a gigantic zombie (Momentus boss) a hundred blocks off... Needless to say I did not stay around there.

i recovered your stuff, and the area is now safe from the marlix's wrath.(i also included half of what the marlix dropped )
your stuff can be found @2225 on smp1


also your horse is alive and well out there: