Happy Birthday, Dear Hogan

Prisoners

 * Colonel Hogan - Bob Crane
 * Corporal Louis LeBeau - Robert Clary
 * Corporal Peter Newkirk - Richard Dawson
 * Sergeant James Kinchloe - Ivan Dixon
 * Sergeant Andrew Carter - Larry Hovis

Camp Personnel

 * Kommandant Wilhelm Klink - Werner Klemperer
 * Sergeant Hans Schultz - John Banner

Semi-Regulars

 * Major Wolfgang Hochstetter - Howard Caine
 * Fräulein Helga - Sigrid Valdis

Guest Stars

 * Mama Bear - Barbara Babcock

Synopsis
Hogan's men plan to surprise him for his birthday by blowing up an ammunition dump, but Gestapo Major Hochstetter has a surprise of his own planned for the crew of Stalag 13.

Story Notes

 * This is the one hundred and fifteenth episode of the series, but it is the one hundredth and eighteenth episode to be shown on television and is the twenty-sixth and last episode shown for the Fourth Season.
 * A bottle of Wisk laundry detergent is superimposed over the closing credits.
 * Mama Bear is played by actress, Barbara Babcock. She is better known to Star Trek fans for her on-screen appearances in two of the original series episodes: as Mea in "A Taste of Armageddon" and as Philana in "Plato's Stepchildren."
 * Klink requests additional guards for the camp. The shortage of guards is mentioned in other episodes.
 * Carter does a dead-on impression of the comedy team Laurel and Hardy.

Production Notes

 * Some scenes which could have been filmed on the outdoor set were filmed indoors, with backgrounds that were obviously painted. Early 1969 weather in southern California was exceptionally bad, and outdoor filming was never done in heavy rain.

Timeline Notes and Speculations

 * This episode takes place in 1944, in the week leading up to Hogan's birthday. Actor Robert Crane's (Hogan) birthday was July 13.
 * In this episode, we learn that the Hammelburg underground organization is trying to re-establish itself. It was broken up earlier that year, as mentioned in The Battle of Stalag 13. Mama Bear, formerly the code name for the Allied submarine in the channel with which our heroes often conversed by radio, is now a flesh-and-blood person and the leader of the new group.

Bloopers

 * LeBeau claims to have baked Hogan's birthday cake, but when it's carried to the party, it is clearly too enormous to have been baked with any of the prisoners' tools.
 * When LeBeau arrives at camp after his meeting with Mama Bear, he has lipstick on his cheeks which was not there when he left the theater.