Here is my monster, Szwink:
Szwink devours the particles of joyful sounds that travel through the air with her tentacles. These particles are invisible to the human eye, but sometimes a laughing human will snort when a clump of these particles are escaping the body. Her favorite activity is sneaking into slumber parties, sledding hills, and playgrounds to observe and absorb. Sometimes she will sing out to amplify the sound. Laughter breeds laughter, right? She is small by monster standards, she can easily hide under end tables and park benches without hunching down.