Hinder. (This Companion can't attack or use its active abilities the turn it comes into play.)
"...I am brought forth."
5 Attack (A) / 5 Health (H)
Frequently Asked Questions
Hinder just prevents Demon Spawn from attacking or using active abilities the first turn it's in play, so causing it to enter play on another player's turn would let you use it on your turn.
Once they are pulled from the side deck, all side deck cards behave like a normal card would. They can be added to your hand, and are sent to the graveyard when destroyed, discarded or resolved.
Side deck cards do not return to the side deck unless they specifically say otherwise.