In general, the Owlbear is the same as Oogar, accept for the fact that before beatdown, Mamosa will "Rear Up", a "buff", before stunning and attacking. You need a good amount of quickness, because mamosa debuffs you with "Piercing screech" which reduces your entire teams quickness rating by 50%. Around 30% hp, Mamosa starts putting a debuff on your pets that reduces healing by 75% and increases damage dealt to that pet.

*Had to edit. Realized I accidentally put my own name, instead of OOGAR's... due to a repetition of adding a B to that name, for my own name. XD

Any tips on the bearhug? Blocking and quick attack doesn't work to stop it.

Quick attack when he's getting ready to bearhug will stop it provided you have enough quickness.

Well first time battling my lowest had: 47.2
and my highest:53.7

for quickness ratings and both plus the inbetween of course got caught. I'm guessing the rating must be twice the amount of oogbar, at the least, although most likely its prob higher, I suggest trying 75% perhaps. if anyone can find his minimum that would b lovely~

Edit: My pets now have 60 and the other 2 55 and so far throughout the battle, when i use quick attack they have been able to avoid, so either 55 or 60 is the lowest spot for no matter wat.

Now that i think of it may also be 50, be when it was just my 53.7 at the times left, i didn't use quick attack and he may just attack the leader, bc my leader was the in between percent before.

Hmmm... Apparently, I am epic enough to now debuff pets while they are in battle. XD
"... I'm guessing the rating must be twice the amount of oogbar, at the least..."

OoGAr is a troll arena combatant... OogBar is the Everquest Ogre and Super Lupora Project (SLP) sylesti breeder, that is commonly mis-referenced instead of Oogar. ^_^

And yes, you need LOTS of quickness rating to avoid being "Bear hugged", due to mamosa's debuff.

My tank has a quickness rating of 57.9 and only avoided Bear Hug 3 out of 6 times... so I would go with 60. Surprisingly I lived through that.

Also, why does it say Bear Hug's duration is 1 turn? That is clearly untrue! and quite confusing.

This is surprisingly easy, defeated Mamosa with my first try with more than 70% health left for all pets. I think 60 would be the limit for the quickness rating, all of mine have above 60 below 65 and they avoided being bear hugged.

Well I guess it's higher than 60... My tank now has 60.5 quickness and still sometimes gets bear hugged... Still beatable of course.

Is that while using quick strike, to avoid the bear hug? If not, you might want to try that on for size.

That is while using quick strike.