Why "Diggle"?

Diggle’s real name is "dgl." And even this is really a nickname. Dgl stands for--
Degenerative (dee-JEN-er-ih-tiv) Leaves

That's because Diggle's leaves get nasty looking when it overeats iron. But scientists got tired of saying, "Well, there goes old 'Degenerative Leaves' again... doing its stupid plant trick!"