I think it's this shadow creature trying to kidnap them based on the word choice. The distorted speech bubble is supposed to indicate it doesn't sound like a friend.
There's a little joke here from the last one that fennec spent the entire evening testing the thing when it tried sounding like Raccoon. Making it answer questions, looking through the door to see what it looks like (it appears wrong once, but comes back looking like Raccoon), and then at last catching it in a lie when she plays rock-paper-scissors with it even though there is no way someone could play that through a door. The creature then loses composure and starts banging at the door angrily.
Here, the creature can't trick Raccoon as Fennec for even a few seconds because Fennec not being responsible is instantly bogus, and the creature just gives up right there.