Zombie Yeti

The Zombie Yeti is the last zombie that the player will encounter, as its first appearance is in either Dark Stormy Night (level 4-10, the second time Adventure Mode is played) or a mini-game. The Zombie Yeti is based on the cryptid Abominable Snowman (Aka:Yeti) that lives in the Himalayas. :3

Suburban Almanac Entry
 Zombie Yeti 

A rare and curious creature.

Toughness: high

Special: runs away after a short while

Little is known about the Zombie Yeti other than his name, birth date, social security number, educational history, past work experience, and sandwich preference (roast beef and Swiss).

Overview
It takes 46 normal damage shots. Appearance changes upon 23 normal damage shots before dying at 46 normal damage shots. Zombie Yetis drop 5 diamonds when first encountered. On every other encounter after that, only 4 diamonds are dropped. It has a chance to run away, so kill it quickly.

Strategy
Just do whatever you do to kill Buckethead Zombies (obviously besides using Magnet-shrooms). If it tries to run away, it can be stopped by planting a Wall-nut or another defensive plant in its path such as the Pumpkin or Tall-nut. If that proves insufficient, plants capable of firing backwards such as the Split Pea or Starfruit can be planted in front of it or an Instant Kill plant like Jalapeno, Squash, or Cherry Bomb can be used.

Gold Farming
One technique is to repeatedly attempt Level 4-10 (once completing it once), the only level in the game where the Zombie Yeti consistently appears. Because the Zombie Yeti, when defeated, yields four diamonds ($4000), the gold farming application is obvious. Do note, however, that unless your version of the game has the Quick Play mode on it, (from which you can access Level 4-10 at whim), it is necessary to reach that point in Adventure Mode, after defeating it the first time. To be able to keep replaying the level, it is of utmost importance that the player does not collect the money bag at the end of the level, or restarts as soon as the Zombie Yeti is killed.

The Game of the Year edition does not allow farming of this zombie, because you can't Yeti farm by restarting level 4-10. Although if you restart and you don't kill him, it will still appear. But if you have both versions, move the saved data from Game of the Year PC version to the old one, and do Gold Farming there.

The other one is use this trick (we can get $200,000 with 5000 suns):

Videos
Video:Plants vs Zombies - Easy Money (No Hack)|Easy Money (No Hack) - $200,000 Video:Wabby Wabbo by Cray-Z -- Plants vs. Zombies Hip Hop Video|Crazy Dave's first single Wabby Wabbo

Trivia

 * The Zombie Yeti has his very own Facebook game. In some pictures of the game, the Snorkel Zombie, the Sun-shroom and the Coffee Bean also appear.
 * The Zombie Yeti appears in Crazy Dave's music video Wabby Wobbo at the end.
 * The Zombie Yeti also appears in the right top corner when the Zombie Bobsled Team appears in Wabby Wobbo.
 * The Zombie Yeti is the only zombie that will not appear until after you have finished Adventure Mode, excluding Invisible Zombies, the Jalapeno Zombie, the Squash Zombie, the Gatling Pea Zombie, and the Tall-nut Zombie.
 * It is the one of the few zombies that can appear without being shown in the seed selection.
 * The Zombie Yeti and the Gargantuar (and its variant, the Giga-Gargantuar) are the biggest zombies. (Not including Dr. Zomboss).
 * Here's a helpful hint: you can mostly find this zombie in the night and fog levels, according to the Tree of Wisdom.
 * In the Mini-game Big Trouble Little Zombie the small version of this zombie can appear but it does not drop diamonds.
 * The Zombie Yeti and the Digger Zombie are the only Zombies capable of walking in reverse direction without being hypnotized.
 * It is rare, but possible to see two Zombie Yetis in one level.
 * The Zombie Yeti and the Newspaper Zombie (once its newspaper has been destroyed) are the only zombies whose pupils are red.
 * The Achievement Cryptozombologist is unlocked by seeing it (Zombologist for Game of the Year, iPhone, iPad, iPod Touch, Android tablets, and Android phones).
 * Even if you have all plants on the DS version, you cannot earn the Book Learner achievement until you kill the Zombie Yeti in 4-10.
 * Along with the Balloon Zombie (while it has its balloon),the Bungee Zombie,the Zombie Bobsled Team (while they have their bobsled) and the Zombotany Zombies,the Zombie Yeti does not have a burnt animation. When they are incinerated, their bodies merely turn black and disappear, unlike other zombies.
 * The Zombie Yeti is one of only three zombies (with feet) that don't wear shoes, the other two being the Jack-in-the-Box Zombie and the Imp (this is assuming that Dr. Zomboss wears shoes).
 * The Zombie Yeti has eight visible teeth, the most compared to other Zombies.
 * If you hypnotize the Zombie Yeti, it will turn left after biting zombies. While it can lose its head, it does not drop diamonds when hypnotized.
 * When you see the Zombie Yeti in Wall-nut Bowling, it takes one hit but still leaves the screen when not killed.
 * The Zombie Yeti costume is available on the Xbox Live Marketplace for 320 Microsoft points.
 * The Zombie Yeti, the Bungee Zombie, the Digger Zombie (if it reaches the left side of the lawn), and Dr. Zomboss are the only zombies that don't target your house.
 * The Zombie Yeti doesn't bend its elbows or knees when walking.
 * It is possible to encounter the Zombie Yeti more than once in a single Survival level, although it will only appear once every flag (or every two flags if in Survival: Hard or Survival: Endless).
 * The Zombie Yeti is one of nine zombies that cannot be used in Versus Mode. This is most likely due to the fact that it doesn't stay on the yard long enough to do much damage, if any at all. Other non-usable zombies include the Zombie Bobsled Team, the Imp, the Balloon Zombie, the Backup Dancer, the aquatic zombies (i.e. the Snorkel Zombie, the Ducky Tube Zombie, the Dolphin Rider Zombie), and Dr. Zomboss.
 * The Zombie Yeti, the Balloon Zombie, the Digger Zombie, the Flag Zombie, the Dancing Zombie (and Backup Dancers) the Zombie Bobsled Team, the Dolphin Rider Zombie, the Snorkel Zombie, and the Ducky Tube Zombie are the only zombies not to appear while battling Dr. Zomboss.
 * It is the only zombie which always drops coins or diamonds, unless hypnotized.
 * This is excluding Dr. Zomboss, who may be considered to drop a trophy (standard, Silver Sunflower, or Gold Sunflower) or a bag of money when defeated.