There's a couple different ones.
It really just depends on what you want, though. There's several different types of "Net" abilities.
Snare spells, such as the Orc Raider's Ensnare ability, stops unit movement, but nothing else.
Entangling Roots is a Root spell, it immobilizes the target unit and stops it from attacking, but does NOT stop it from casting spells.
Stuns, such as Storm Bolt, aren't usually considered snares but that's technically what they are. They stop everything on the target unit, from moving, attacking, and casting spells.
All of these spells can be used on both air and ground units and are great alternatives to Arial Shackles.
There's a couple more types but I can't remember...