It's lick actually stacks twice over 20 seconds. Frogs my favorite creature. Really great for taming without use of tranqs. I knock out a trex in decent time once it's over 400% damage. Players in flak armor don't stand a chance once you've locked them. It's great lol. Just lick not hop away till they faint.
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.