of the Green Lantern
as published in DC Comics
first appeared in The Flash #238
The sidekick is a well-known part of comic stories allowing a strong hero to become more accessable to the readership. Hence, Batman had Robin, Captain America had Bucky, Aquaman had Aqualad, the Flash had Kid Flash, and the Green Arrow had Speedy. In all these cases, the young boys who read these comics were better able to identify with the stories for the addition of the sidekick. So, the inclusion of Itty, who was initially introduced as a version of a house plant, seems an odd choice for a sidekick for the popular hero the Green Lantern.
Itty was introduced in 1975 in a back-up Green Lantern story in The Flash #238. The Green Lantern (in this case the Silver Age hero Hal Jordan) had been sent by the Guardians of the Universe to a distant planet. He was to stop a group called the Ravagers of Oly. This group of aliens was trying to gain membership in a great interstellar empire and was forced to prove their merit. The Ravagers were thus assigned as their initiation to reverse the story of creation set out in the Bible in the book of Genesis. This type of stuff went on all the time in 1970's comics, but it is good to know that the Gideons have successfully gotten bibles in the nightstands of the Red Roof Inn on Alpha Centauri.
The Green Lantern arrived at a planet called Vivarium which acted as a cosmic green house for the Ayries, a group of creatures that looked like an orange and purple flowering plant but that possessed a limited intelligence. The Ravagers were using a robotic weapon to attempt to destroy the Vivarium and with it the Ayries. The Green Lantern attempted to stop the Green Lantern and would have been felled by a Ravager weapon if not for the fact that one of the Ayries nudged him, alerting him to the danger. Green Lantern was able to defeat the robotic device and save the Ayries. As he left, one of the Ayries accompanied him, riding on his shoulder like a bizarre corsage. The Green Lantern named his new companion Itty because it was small and thus "itty-bitty."
Itty and the Green Lantern were traveling companions, which undoubtedly got strange looks from villains and other heroes ("Why is the Green Lantern talking to his flower?") Itty was a useful companion to some extent, even saving the Green Lantern from Jason Woodrue, the Floronic Man, by using the Green Lantern's power ring to free him from a tree sap prison.
Eventually, Itty began traveling with Jordan less and less and spent his time on earth with Jordan's cousin Harold Jordan who was also the hero Air Wave. It was never indicated how long Itty was on earth when he seemed to die. Itty became unresponsive and did not move and eventually, it was determined by his friends that he had died. They buried him on the estate of Carol Ferris, Jordan's girlfriend. Soon after, a blob-like creature attacked the Ferris estate and the Green Lantern attempted to battle it, but found that it was immune to the effects of its ring. The creature also seemed to have the ability to absorb calcium, which was discovered when it destroyed a concrete structure by drawing out the calcium.
Eventually, it was discovered that the blob creature was the next stage in Itty's development and by feeding it more calcium, the Green Lantern was able to help his friend on to its final stage of development in which it was a big blue humanoid. Itty apologized for the trouble he had caused and then teleported himself back to the Vivarium to be with his people.
It was later revealed that all of the Ayries at the Vivarium had been killed but one who was attacked by the Ayries' (who were also known as the Lasma) enemy, the Laroo. The two, Itty and the female of his species, returned to Earth, seeking the protection of Hal Jordan from their attackers. Jordan with Itty's help was able to turn back the Laroo attack. Afterward, Itty and his mate left for the stars, leaving Hal Jordan to care for their thousands of offspring, which he promised to care for by building a new Vivarium.
Since soon afterward, Jordan went nuts, killed most of the Green Lantern Corps, tried to remake time, died, and is now the new Spectre, it is quite possible that the immature Lasma were left to their own devices. So if the potted plant on your desk at work suddenly turns into a blob and tries to the suck the calcium out of your teeth and bones, don't say you didn't have any warning.