RPGMemes

Hm...

1. One Decanter of Endless Water
2. Two items that you can attack to this decanter
3. Two castings of Magic Mouth on these items:
   1. Condition: "(The decanter is uncorked and thrown, then gets within 1 foot of a creature other than who has thrown it OR six seconds after someone says 'Geyser') AND nobody has said 'Frixfraxfrux' in the last six seconds". What to say: "Geyser".
   2. Condition: "Six seconds after someone says 'Geyser' AND nobody has said 'Frixfraxfrux' in the last six seconds." What to say: "Geyser".
4. Resilient Sphere in a Ring of Spell Storing given to the familiar.

Tell the Familiar to ready an action: cast Resilient Sphere on a given enemy just as the decanter is within 1 foot of them. Then uncork the decanter and throw it at the enemy.

When the Decanter is within 1 foot of the enemy, your familiar casts Resilient Sphere to encase the enemy, and MM1 activates, saying Geyser. The decanter starts producing 30 gallons per round because MM1's activation activates MM2, and MM2's activation activates MM1 again. And so on.

I'll switch to metric because I like units that actually make a modicum of sense. Let's say a medium creature is at most 8 feet tall, that's 2.4 m, the enclosing sphere has a radius of 1.2 m. The decanter produces 30 gallons per round, that's 113 liters. The enclosing sphere's volume is 7.23 m^3 which is 7230 liters. A bipedal medium creature that tall is likely going to weigh around 150 kilos, if it's a humanoid then its density is roughly equal to water's so that's 150 liters of the sphere occupied by the creature. This leaves us 7088 liters to fill which is unfortunately much more than what the decanter can fill in 1 minute. In fact, it would take around 6 minutes to fill the sphere.

Bummer.

Maybe you can tie together 10 decanters?

(Though TBF a bit of alchemy could likely create a CO-producing bomb. Doing that with the familiar-spell-storing-ring trick could work, enclosing the enemy in a sphere of lethal gas for 1 minute. But even that is an awful lot of prep for suffocating someone when you could use the same spell slot to summon an azer and hug the enemy to death or 4 magma mephits and roast them in their armor.)