Horn-blowing Wizards

There are a few different kinds of horns that enterprising adventurers can obtain: horns of blasting, horns of collapsing, and for our underwater friends, a horn of the tritons, although it is more of a conch than a horn. But certainly the most cheerful of the horns that a roving bard or sticky-fingered thief can pick up is the horn of bubbles. 

From the Dungeon Masters Guide: This musical instrument will radiate magic if detected for. It appears as a normal horn, or as one of many magical ones. It will sound a note and call forth a mass of bubbles which completely surround and blind the individual who blew the horn for 2-20 rounds, but these bubbles will only appear in the presence of a creature actively seeking to slay the character who winded the horn, so their appearance might be delayed for a very short or extremely lengthly period.  

Now that is a weird magic item. Fing the Merciless might find the horn in a slag heap, blow it, feel like nothing has gone on, only to discover that when they are about to tangle with a ogre family, they are surrounded with a thick mass of bubbles. I think this is one of those magic items that seems bad when you first get it, but once you figure out how to use it, can be quite fun to surprise on one's enemies. Or maybe it is the other way around.

I also imagine that all the bubbles make a cartoonish popping sound when then break.

"The Wizard Blew His Horn" is one of the Moorcock numbers from Warrior. It isn't great, but it is weird.