Well, most creatures can push parcels, flowers, etc, so its kinda hard to 'trap' them without field runes.
What you can try is to use the same technique used to trap the true asuras in the mirror of asura palace.
This is how the ones north-east of the area are trapped:
As all the creatures in tibia, try to go back to their respawn area when you are out of the screen, when you move the 2 true asures to the south east room and trap them in the north area of it, they keep trying to move back to their respawns zones in the north 'through' the wall.
Maybe you could use this technique somehow in mammoths, for example:
Hope I helped xd