I've never put anything in the crib yet. He sleeps with a sleepsack on. DS is sort of a wildman when he sleeps. He flops all over, turns, etc. I feel like anything I put in there would just get tangled up with him, or end up pushed into the corner.
FWIW, when DS was around that age, he went through about a 1-2 week period where bedtime was total torture. I don't know if it was teeth or what his deal was. I started to get super anxious about it. After a few weeks, he was back to normal, but I totally remember that. It was awful.