Plate 28 from "A celestial atlas" as a generic die drop table

Source: Wikipedia

Print out the above on a oversized paper, and drop dice on it to create a random encounter.

E.g. drop three die and use one to determine the monster/creature, one to determine weapon, and the last to determine weakness/weak spot on body.

Or instead of dice: put it on the wall and throw dart! Or dip your dice in paint and throw those instead on the wall.

Anyway, you could put a meaning to different dice and drop those on the atlas above and interpret the results and be very happy according to this table:

1d4: Major feature of monster (e.g. drops on wing = flight)

1d6: Minor feature of monster

1d8: Weakness

1d10: Desire/motivation

1d12: Number of lines touching underneath = hit die

1d20: Last kill was this

And - AND! - the creature's reaction towards the party is based on the total number of even/odd dice; more even dice = happy creature, more odd = not happy.