अगजानन (agajAnana) ...

A Sloka that almost sounds like the sequel to the previous Sloka is the following:

अगजानन पद्मार्कम्
गजाननम् अहर्निशम्।
अनेकदन्तम् भक्तानम्
एकदन्तम् उपास्महे॥

agajAnana padmArkam
gajAnanam aharnisham |
anekadantam bhaktAnAm
ekadantam upAsmahe ||

अगजानन - अग (that which does not move, i.e., mountain) + ज​ (born of), this refers to Parvati who is Himavan' daughter.
आनन् - face
पद्मा - Lotus
अर्क​ - Sun
गजाननम् - Elephant faced
अहर्निशम् - day and night
अनेकदन्तम् - giver of many boons
भक्तानाम् - devotees
एकदन्तम् - one-tusked
उपास्महे - bow down to, meditate upon

O' Lord Ganesha, just like the Sun makes the Lotus bloom, your presence lights up Parvati's face. O' Single-tusked Lord who bestows unending boons on his devotees, we bow down to thee day and night!

I really love the play of words in this Sloka that almost makes successive phrases sound like antonyms! To finish off, here are a couple of stories explaining Lord Ganesha's elephant head:
Once goddess Parvati, while bathing, created a boy out of the dirt of her body and assigned him the task of guarding the entrance to her bathroom. When Shiva, her husband returned, he was surprised to find a stranger denying him access, and struck off the boy's head in rage. Parvati broke down in utter grief and to soothe her, Shiva sent out his squad (गण) to fetch the head of any sleeping being who was facing the north. The company found a sleeping elephant and brought back its severed head, which was then attached to the body of the boy. Shiva restored its life and made him the leader (पति) of his troops. Hence his name 'गणपति'. Shiva also bestowed a boon that people would worship him and invoke his name before undertaking any venture.

However, there's another less popular story of his origin. Shiva asked Parvati to observe the punyaka vrata for a year to appease Vishnu in order to have a son. When a son was born to her, all the gods and goddesses assembled to rejoice on its birth. Lord Shani, the son of Surya (Sun-God), was also present but he refused to look at the infant. Perturbed at this behaviour, Parvati asked him the reason, and Shani replied that his looking at baby would harm the newborn. However, on Parvati's insistence when Shani eyed the baby, the child's head was severed instantly. All the gods started to bemoan, whereupon Vishnu hurried to the bank of river Pushpabhadra and brought back the head of a young elephant, and joined it to the baby's body, thus reviving it.