Mutant Vegetables

 were NPC during the Terwilligers 2015 Event that gave event currency to get prizes. They were appearing on the streets of the Player's Springfield and their Neighbors' Springfields. When the player tapped them, they were getting event currency.

Rewards
There were two different ways to collect them:
 * In the player's own town, they rewarded 7 Spades AND 4 Fertilizer, 4 Corn or 1 Mutant Seed.
 * In their Friend's Towns, they rewarded Spades for the first 90 actions (1 per action).

Trivia

 * A maximum of 40 mutants could be found in your town at a time.
 * One new mutant was spawned every 10 minutes.
 * Farming License is available to double the reward in the player's Friend's Towns.
 * From April 28 to May 6, 2015, before the Level 52 update, the mutants were still visible on the streets of the Player's Neighbors' Springfields.

Skins
appeared in four random skins. However these skins had no difference except for the look.