Papyrus
Skeleton (UT monster)
His known abilities include summoning bones, blue attacks (hold still to avoid damage, great for forming danmaku.), a special blue attack (turns enemy's soul blue and enforces gravity on them, grounding floaters), pseudo-telekinesis using the same sort of magic as said special blue attack, summoning gaster blasters, and cooking.
He is almost always happy, and is quite quick on his feet. He's fairly good at dodging. The bones he summons can be bullets (purely for attacking but have some visual charm) or actual physical bones, which can have a number of uses. On death, his body will turn to dust. Since he is not undead in the traditional sense, silver, holy energy etc. don't affect him any differently than they would the next guy.
His body is over 70% magic, similar to how humans are mostly water; effects which drain or permanently dispel magic harm him. Because monster magic is tied so closely to emotions, the strength of his attacks grow with his own intent to cause harm (his attacks are usually pretty non-lethal because of this), and an attacker with strong intent to cause harm will find their attacks to cause him greater harm than normal. Additionally, he is easier to harm in times of stress, emotional turmoil, or other emotionally vulnerable states, and more difficult to harm when emotionally sound; moreso when he holds contempt (and especially defiance) for his attacker, but this is very, very rare thanks to his personality.