100% melee damage is 20 base damage with beelzebufo sweep attack = 60 torpor over 10 secs. A second sweep attack within that 10 secs will only deal additional damage. 1000% melee damage will do 600 torpor over 10 secs with sweep attack :)
These oversized toads are easy to tame. All you need is a bola, tranq arrows and meat to tame them. Their food drops faster than their torpor, so you won't need that much narcotics. Be careful not to tame one if there are others nearby.
So, i found this creature in/around the swamp. I tried throwing bola at it, and it worked! But first, you have to gather Narcoberrys or Narcotics. The knock-out meter is going down pretty fast for this creature. Just give it some meat and ready! I tamed myself one, when i made a new base around the swamp! Its strong - he killed a Sarco! And didn't even get much damage. I recommend this creature 👌