1 Prof. Jones: I say, being a felucca owner, aren’t you worried about the vagaries of the Nile? Seasonal flooding and dry spells?
2 Felucca owner: No, I trust in Hapi, the ancient god of the Nile, Lord of the Fish and Birds of the Marshes.
3 Felucca owner: Hapi would never let the Nile turn into a dry, dusty river valley.
4 Prof. Jones: I see. Don’t wadi, be Hapi, eh?

Hapi is specifically the Ancient Egyptian god of the annual flooding of the Nile River. Hapi was considered male, but as the god of the Nile flood he represented the fertility associated with the annual flood, and was depicted with pendulous breasts and a large belly resembling a pregnancy. Because of this fertility, he was also considered the "father of the gods". When depicted in colour, his skin was blue or green, like the waters of the Nile.

Hapi should not be confused with the other god of the same name, Hapi, the son of Horus. This Hapi was one of the four Sons of Horus, charged with protecting various organs of the dead in the afterlife. Each son was associated with one of the four canopic jars into which the removed organs of a mummified body were placed for safekeeping in the afterlife. Hapi was responsible for protecting the lungs, while his three brothers—Imsety, Duamutef, and Qebehsenuef—looked after the liver, stomach, and intestines respectively. Canopic jars typically have lids carved into the shape of the heads of the four Sons of Horus - Hapi having the head of a hamadryas baboon, while his brothers had heads of human, jackal, and hawk.

The second Hapi has nothing at all to do with this comic, other than having the same name. Presumably "Hapi" must have been like "John" when Ancient Egyptian gods were choosing names for their kids.