Until School of Crock, Poof only says his own name frequently ( "Poof, poof" ) but some of the characters strangely understand this. The only known person/fairy who seems to be aware that Poof just says his own name frequently appears to be Foop as shown in Spellementary School.
When Poof said "I want my rattle", he sounded like what he always was when he said "poof, poof". But when Poof speaks again, he sounds like Timmy in a deeper voice.
By the end of "School of Crock," Foop is thankful for Poof saving his life and apologizes for trying to annihilate him all that time. This may indicate that after this episode the two will be finally cool with each other.
Poof's first words in a sentence were "Yo, man. This gonna be so cool man. We're going to be bumpin', man. Tryin' to help the boys out. You know how we do it. You feel me, dawg?" (Grow Up, Timmy Turner!). Although, he had already said single words, like "mommy", "daddy", "Crocker" and "Timmy". He also said "Hide and seek!" in He Poofs He Scores.
Starting in "School of Crock", Poof learns how to talk permanently, his first words being "I... want... my... rattle!".
Apparently, Poof thinks that Timmy should get rid of his pink hat.
In "Wishing Well", he appears to have a great bond with Timmy, since he was the only other person enjoying the wishes that Timmy was making (Cosmo and Wanda were just worn out due to too many wishes being made). When Timmy was taken to Wishing Well due to overworking his godparents, he became so sad that he continued to cry until Cosmo gave him a Timmy doll which stopped Poof from crying.
When someone touches Poof, his body will squeak. This was never explained.
Poof was introduced in "Fairly Odd Baby", which also revealed that he was a boy and that Cosmo, Poof's father, was the last baby born before him. He has appeared in every episode since then until "Let Sleeper Dogs Lie".
Poof was in the 2009, 2010 and 2011 Kids' Choice Awards.
In "Poof's Playdate," Timmy wished that all fairy babies changed into grown ups. But Poof did not change into a grown up.
Poof doesn't have teeth, but in "Poof Proof", Poof has one tooth. In addition, Poof has a full set of teeth (or two) in some episodes.
When Poof sucks his thumb in "Fairly OddBaby", he floats with a glow around him, but immediately, Anti-Cosmo interrupts it. Perhaps when he sucked his finger, it also had powers.
On Wishology: The Big Beginning, when all the fairies in Fairy World turn into gumballs and the fat kid buys Binky Abdul and chews him, all the fairies (including Poof) cry out "AAAH! The horror!" as if like Poof can talk in complete sentences. Same goes with the fairies yelling "AAAH! The quarters!"
Poof has appeared in the alternate-universe in Turner Back Time even though he shouldn't as he was a wish made by Timmy.
Poof has appeared in the Dimmsdale Tales' title card even though he doesn't appear in that episode himself.