Effective on Karkinos, Yutyrannus, Rock Drakes, Thylacoleo, etc, etc, but the main creature you want to use this one is wyverns. Absolute joke to get wyvern milk with a few nets (bring a few in case you miss). A low level female wyvern can be knocked out with a good quality crossbow before even reaching the 20 second mark, and it will be trapped for a total of 60 seconds. It will be unable to move, use its breath attack, or bite, letting you blast it over and over. Take the milk, kill the wyvern, and get out of there. Several minute ordeal and you’re done.