* Jekyll has (eventually) an adopted son and Nemo has a foster daughter in ''FanFic/ThePrivateDiaryOfElizabethQuatermain''.
* Tony Stark becomes this to his adopted son Harry in the ''Literature/HarryPotter''/''IronMan'' crossover fanfic ''Fanfic/HarryPotterAndTheInvincibleTechnomage''. It is also demonstrated that many of the heroes feel this way toward their allies' children.
* Spyro from ''FanFic/TheLegendOfSpyroANewDawn''. He is pretty protective of his adopted egg, just like [[MamaBear Cynder]], but a much bigger PapaWolf is Ember's father, Blaze. When [[TheDragon the Warden]] has Ember overpowered in their battle, Blaze blasts him, despite [[AgonyBeam the Warden's collar inflicting debilitating pain]] on any of the cursed slaves who attacks or touches him in anyway. Once [[spoiler:the Warden's collar is destroyed and the curse is broken]], Blaze tears through the cage holding him and [[FoeTossingCharge a mob of]] [[EliteMooks Warrior Gargoyles]] to get his claws in the Warden.
--> '''The Warden''': [[OhCrap Uh oh...]]
* [[AlternateUniverseFic AU]] ''DevilMayCry'' fic "[[http://www.fanfiction.net/s/6822576/1/Like_Father_Like_Son Like Father, Like Son]]" has Dante exhibiting his demonically-protective side when he finds his son Nero injured courtesy of a police officer with temper problems, and when Nero is later threatened by members of the mafia. The second time Nero gets threatened by the son of a mafia head, a partial Devil Trigger sends the man leaving with tail between legs. And when Dante finds the demon Baul, who had all but put Nero near Death's door... Cue UnstoppableRage and RoaringRampageOfRevenge with a dash of ThereIsNoKillLikeOverkill.
* In ''[[FanFic/HarrysNewHome Harry's New Home]]'', Snape will go to any lengths to protect his ward Harry, even if it included breaking rules or facing the Dark Lord and Dumbledore (if necessary) to do it.
* In ''Series/{{Supernatural}}'''s [[http://www.fanfiction.net/s/6536156/1/Crossing_the_Line Crossing the Line]], John Winchester kills a human being for the first time because [[spoiler: it was heavily implied said person had molested/sexually assaulted a ten-year-old Sam.]]
* In the FanFic/UltimateReImaginings, Clint is this towards Joey as he once nearly killed the boy's ''actual'' father for putting him in the hospital and breaking his arm when Joey had been twelve.
* Both Mr. Squall, [[TheIncredibles Mr. Parr]], and [[spoiler:Chomper the TyrannosaurusRex]] in ''Fanfic/RiseOfTheGaleforces.'' Subverted and later inverted for [[spoiler:Chomper's case, though, when his protectiveness of his fellow rexes [[EyeScream costs him his eye]] - but also makes his ''own children'' angry enough to [[KarmicDeath horribly slaughter]] the BigBad.]]
* In ''FanFic/PonyPOVSeries'', Havoc, AnthropomorphicPersonification of Mass Hysteria, is an odd case. He's an AbusiveParent, and he'll mock his children if they get beaten up by people defending themselves from them. However, any who harm them unprovoked will know his wrath.
* In ''LordOfTheRings'' fanfics such as [[http://www.fanfiction.net/s/1179397/1/An-Eye-For-An-Eye An Eye For An Eye]] or [[http://www.fanfiction.net/s/2636049/1/The-Roots-of-Evil The Roots of Evil]], it is a sure way to trigger Legolas's BerserkButton is by hurting [[HeterosexualLifePartner Aragorn]] in any way, shape or form. It is the same with his older adopted brothers [[BigBrotherInstinct Elladan and Elrohir]], who must have gotten it from their father Elrond. All four elves have no hesitation to resort to ''killing'' anyone who dared lay a hand on Aragorn. And those times when they found that Aragorn was tortured and near death ... well, to say it did not go well with those people is putting it lightly.
* ''Fanfic/KakashisKid'', from Manga/{{Naruto}}, portrays Kakashi as this.
* Orochimaru is one in the Fanfic called [[http://www.fanfiction.net/s/4070794/1/A-Fathers-Wrath A Father's Wrath.]] In this story he is Naruto's father instead of Minato.
* Kakashi in a FanFic/AGrowingAffection becomes an adoptive ActionDad.
* Former D.I. Michael Lestrade in ''Fanfic/ChildrenOfTime'' (his son-in-law, Literature/SherlockHolmes, is also slated to qualify).
* [[Series/KamenRiderFourze Takashi Satake]] in ''[[FanFic/{{Horseshoes and Hand Grenades}} A Month of Sundays]]'', who responds to fighting a large porcelain doll in a CircusOFFear is to punch it in the face.
* ''Fanfic/ChildOfTheStorm'' has Thor, God of Thunder and Lightning (not Reason and Understanding), is the father of the titular child, Harry and a fairly epic PapaWolf. Raise a hand to Harry, even threaten him, and you will face the full wrath of the Thunderer, usually delivered via a supersonic Mjolnir and a record breaking bolt of lightning or several thousand.
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