Over 2 days

[Vasken]

I find the "kill a rare, another spawns" rule to be utterly bizzare. Killed a passing rare in Dragonblight after a camp in Sholazar. Aotona was up when I checked again. Found someone to tame Loque. King Krush spawned mere seconds afterwards. Might entirely be coincidence, but it's freaky!

[Wain]

I have it from a dev himself (and have seen the actual tools involved) that no rare spawn in Northrend is linked, they all share separate respawn timers, EXCEPT for Vyragosa and the Time-lost Proto-Drake who share a spawn timer.

And that the spawn times on the beta (and presumably the PTR for 4.1) were the same as what was kept for live. It's just more obvious when there are few people around that there can be many rares up at once. And the fact that you can survey them and not kill them debunks the theory that a fourth must be spawning soon after you killed the third.

[Pent]

I always like the instances when King Krush and Loque are both up at the same time.

Seen it happen at least 3-4 times.

[Victorelle]

LOL! Whats next X3

[rhythm]

For the 3 days I camped him, he spawned 3 times for me. 23 hours(killed), 19 hours(Nelf beat me to him), 21 hours (tame), 14 hours (my wife tame)

Unfortunately from the reading and my personal experience shows his spawn time is extremely poop.

[Ziarre]

From digging around Petopia and Wowhead, a broad range seems to be 12-24, more commonly 20-24. Shorter or longer seems to be fairly uncommon, my personal runin with his timer was 21.5 (wish I hadn't known though, since the first sighting was a kill after failing to find him a home--I was too low!).

[Ironale]

Well after 15 hours i decided to get some shuteye. Ill probably camp for another couple of hours this morning, then ill go do some quests or something.

[Maladramatic]

Arc is one of the ones that I feel has a very large and somewhat rare spawn. I've never been able to force him to spawn and I've never been able to predict an upcoming spawn. I could guarantee a Gondria, or a Krush for a friend who wanted it though, so it was annoying. I've seen people sitting in one place for days with the bear, most actually at the keyboard too and end up empty handed. I myself took months to get him because I simply refused to sit for what appeared to be a 24-28 hour requirement. (I'd already done it for Skoll, likely missing him in one of his other spots in the mean time).

In the end, I got lucky and logged in after leaving my hunter parked in the inn for about 3 weeks and he happened to be there one morning as I checked.

[Griffley]

I got all my pets this way:

Go out with friends (or watch movies or play BGs instances whatever)

And when you get back home at 4/5 am, just check the spawnpoints of your fav pets before you go to sleep

It will surprise you how often you will find them

[Ironale]

Right after 2 days of nonstop camping he finally spawned. My god i nearly had a heart attack! I was standing on his exact spawn point and suddenly he spawned..im still in shock. It happened like 10 mins ago...god

Anyway, info ahoy! I forgot to look at my clock to check the time he spawned but the tame finished at 10:58pm GMT (11:58pm Server time) on Silvermoon-EU. Since i started tming the SECOND the bugger spawned i assume he spawned at either 10:57 or 10:58pm GMT.

I have been in this spot for around 14 hours yesterday. Then at 5am i went to sleep. Woke up at 10am and have been camping ever since. So its possible he spawned between 5am and 10am and someone killed him. That would mean he has around a 12 - 14 hour spawn. Personally? I belive its random. I belive it can be 8 hours, 12 hours, 16 hours, 20 hours or 32 hours. RNG is RNG.

[Ethian]

was out mining abit,decided to fly over the river,and KaBLAM!
There he was!and just 5 mins ago Ghostcrawler decided to show up!
lucky night;)

[Meldiren]

Arcturis was the hardest of the original 4 spirit beasts for me....simply because he is so camped. I made it a mission with a guild buddy....he found him at 9 AM server time. so next day, i logged on at 9 AM server time...and there he was.

There is a lot of luck AND patience involved in all rare tames. Terrorpene and Loq for me were both pure luck.