Gable board/tympanum/หน้าจั่ว naa4 jua3(?) above the entrance:
Bpaang naak bprohk (Buddha sheltered by 7-headed naga) at the top:
In the third (or sixth?) week after Buddha attained enlightenment, Mara attempted to distract him by causing a rainstorm. The naga Muchalinda (Mujarin) then sheltered him & coiled its body to raise him above the rising floodwaters. Thais assign this Buddha image to represent Saturday. The cat was born on a Saturday but doesn't believe in such stuff, though it will take photos of it ;)
In the middle are the five Buddhas of the present universe:
Below them are five animals (L-R: rooster, naga, singha, turtle & cow) that brought them up in this story: a storm blew a crow's nest containing five eggs out of a tree & they landed on a riverbank. Each egg was discovered by a different animal, which took care of the eggs until a human baby boy hatched from each. The boys grew up to become Buddhas, each named after the animal that brought them up.
Kukusanto (aka. Gakusandho) was brought up by the rooster & became the first Buddha in this universe. He was followed by Konakhamano (aka. Gonakamano), who was cared for by the naga. A turtle raised the third, Katapo (aka. Gassapo). The fourth, Khotama (aka. Sakyamuni or Gautama), taken care of by a cow, became the first Buddha in written history. The egg of the fifth, Ariyametai (aka. Maitreya) was hatched by a singha (lion) & he will be the future & last Buddha of this universe. He is depicted without the halo as he is still a Bodhisattva & has yet to enter nirvana.
The Pali romanisations of the names here may not be perfect - they were translated by a novice monk for whom Pali is the subject 'I dislike the most'. A mural of the story & the Thai version here & the Khmer version here (story of Bondat Protib).
At the bottom is Rahu eating the moon:
The Hindu Gods wanted to obtain the elixir of immortality by churning the ocean of milk, using Mount Mandara as a pole & the serpent Vasuki as a rope. To do this the Gods & the demons took turns to pull on opposite ends of the serpent coiled around the mountain, rotating the latter & stirring the ocean. Treasures emerged as they churned, including the sun & the moon, & finally the elixir. The demon Rahu disguised himself as a God in order to drink some of the elixir, but the sun & the moon spotted him & alerted the God Vishnu, who sliced off Rahu's head before the elixir could go down his throat.
Till this day the immortalised head continues to chase after the sun & moon for revenge for telling on him. When he catches up with either, he swallows them, causing solar or lunar eclipses. The sun & moon will disappear into his mouth & then fall out & reappear as he lacks a body. Those who have passed through Bangkok's Suvarnabhumi Airport would have seen the big fat sculpture of the churning of the ocean of milk. Click here for the depiction of this story at Angkor Wat.
Here in Muang Khua, locals have attached a solution to Rahu right below him - a fluorescent light tube ;)