A longer tail? Oooh, I like the idea of it being prehensile! Strong enough to grab wrong-doers and throw them into the air, straight into the path of our lasers!! Then BAM!!

...Well, of course the laser would be set to stun. It's only fair, right~? No hurting anyone without reason.

[What a backpedal. Like they're good people or something, right? Haha...well. Mettaton really wants to turn over a new leaf. Less violence, and hopefully less killing. That way he can get back to what's really important.]