In Star Wars we see many Twi'leks, which all have lekku on their heads. The main Twi'leks we see are female, and one of the only male Twi'leks we see is Bib Fortuna. Bib Fortuna's lekku are very long; so long, that he has to roll it on his neck. The Female Twi'leks with lekku are all short, but all the female Twi'leks we see are relatively young, while Bib Fortuna is very old.
Does the length of your lekku grow as you get older?