I once daydreamed about a scientist living in the backwoods while conducting research on and raising a tiny eldritch tentacle creature. Seeing which foods it liked, testing its memory and intelligence or simply gently caressing it, then writing down his research notes at the end of the day, unaware that every time he came in direct contact with the creature, she would slowly assimilate itself closer to that of a human.
As it slowly grew and became more conscious and affectionate, it would start slipping out of it's enclosure to gather more data while the researcher was sleeping. Collecting his saliva, a sample of his skin, and even his mind, how he thinks and what he thinks.
Over time, as she gathered more data, she began changing form. Developing a humanoid face and body but while still keeping a squishy and soft body with tentacles in the extremities, trying to communicate back but only making squeaky noises at first, attempting to imitate human ways of showing affection like hugging with her arm sized body and so on.