Different kind of possession, but since we're on the topic... can DMs possess your animal companion? It's more curiosity than anything else motivating my asking, but if they can, could be fun for things like having your wolf sniff out a trail to track someone down as one example. Might be impossible to do familiar-style possession due to game limitations but if this is possible and the DMs are willing, you could have some more in-depth RP involving your companion. I realize that not everyone would be cool with a DM playing their companion, since they might have a specific personality or behavior patterns the player doesn't want to compromise but if the player and DM are in agreement, what's the harm?