The famous promo Cactus Jack (Mick Foley) made toward the ECW fans, explaining why he had, seemingly out of nowhere, turned heel on Tommy Dreamer and sided with Raven, was brought about after seeing a sign in the crowd reading 'Cane Dewey'. Dewey was his three-year old son at the time. Ironically, Foley, in real life, actually was glad for the sign as it gave the character a reason to turn, something he was struggling with as he had no idea how the character was supposed to justify suddenly turning heel. The guy who brought the sign felt immensely guilty for it, up till Foley actually told him that it had helped him out and that he had no hard feelings on the matter.
Kamala was enough of a threat already but some foolish individuals decided to try and attack his various managers anyway, making him even more dangerous.
In Real Life, Vince McMahon is an example of this. As Triple H said, "Hurt his wife or kids and he will use every resource he has to destroy you." And don't even get us started on what happens if you try to touch his company.
CM Punk's feud with Rey Mysterio Jr started with Punk interrupting Rey, who was celebrating his daughter's birthday. Eddie Guerrero brought this side out in Rey as well in regards to his son, Dominic.
William Regal showed this previously unseen side of himself due to HHH's attempts to manipulate Eugene.
Subverted again when Cody turned on Holly and teamed up with Ted DiBiase Jr. , costing himself and Holly the tag team titles in the process.
James Storm turned into this on one episode of TNA Impact, when Bobby Roode made a sexual comment about Storm's young daughter.
Uncle Elmer (Hillbilly Jim's uncle) was ordinarily an enormously fat, lazy, slow-witted buffoon. But threaten his nephew or one of his own two boys, and he might just sit on you until you beg for mercy.