"Christmas Groaners!" joke

A youngster drew a Christmas scene that showed Santa, sleigh and reindeer.
There were the regular eight and Rudolph plus a strange looking tenth animal.
The addition looked like a cross between a reindeer and a cow with a green
nose. The youngster explained that it was. . . Olive, the udder reindeer.
The same creative youngster drew a nativity scene in Sunday school. In addition
to the normal contingent of characters, there were three very tiny men wearing
crowns. He explained that they were. . . wee three kings from the Orient.
His baby Jesus was sleeping on a scale, his. . . a weigh in the manger.
The last bit of creativity showed three robed men standing in a flower bed
under a ftill moon. They were. . . the shepherds who watched their Phlox by
night.