Jimmy could communicate in Morse code. Naturally this would require that an Eldritch Monstrosity could understand such a human concept, but usually such creatures are known for driving humans mad -- not the other way around.

So, all Jimmy needs to do is create a series of tall and short statues, depicting Ichthala the All-Devouring Mother (or as he calls her, Mom) and her dread offspring. Sure, most humans would see them, investigate, and go mad -- but once the raging cultists have been put down, someone would have the bright idea of finding a code in the statues. (Though they might be comfused by the message, "Come play ball with Jimmy.")

Jimmy could communicate in Morse code. Naturally this would require that an Eldritch Monstrosity could understand such a human concept, but usually such creatures are known for driving humans mad -- not the other way around.

So, all Jimmy needs to do is create a series of tall and short statues, depicting Ichthala the All-Devouring Mother (or as he calls her, Mom) and her dread offspring. Sure, most humans would see them, investigate, and go mad -- but once the raging cultists have been put down, someone would have the bright idea of finding a code in the statues. (Though they might be confused by the message, "Come play ball with Jimmy.")