We introduced a pillow to Spencer at 16 months when she went to a BGB, Masyn just used her teddy bear like a pillow until she went to a BGB at 2.5. Spencer never moves in her sleep so it changed nothing, in fact I don't know if she even sleeps on it. Masyn moves so much that I usually find her dangling off the edge of the bed, though she does start the night on her pillow!