In Wigu, Quincy Tinkle may be a happy, somewhat dumb guy, but if Wigu or Paisley are harmed he will go to great lengths to get revenge. To date, Quincy has annihilated an alien insect that bit Wigu, fought off a group of Plesiosaurs with nothing but a knife when they attacked the Tinkle family van, and almost murdered Hamburglar after the latter hospitalized Wigu.
Bob rarely loses his composure much beyond his stock look of Dull Surprise. We've seen him scared or frantic upon occasion, but the only times we've seen him furious are the times Jerry has threatened Molly with a gun. When Bob believed she'd actually been hit, he launched himself at Jerry (who was armed) and tackled him without hesitation.
Daisy Owl: Mr. Owl is a Papa Wolf, despite being an owl. He's willing to go up against NASA armed only with a bear if it means saving his kids.
Hon Arkraptor from Tower of God is a Papa Wolf who failed to protect his daughter. As a result, he is overcautious whenever it comes to Miseng, who resembles her. This includes trying to fail her so she gets out of the inner section of the Tower and beating up the creeps that get too close to her. Their relationship is rather shaky, to say the least.
In Megatokyo, Ed learned the hard way that just because Ibara may be a jerkass that leeches money off his daughter Junko doesn't mean he takes kindly to having a shotgun pointed in her general direction.
In Exterminatus Now, Lothar Hex's adoptive mercenary father is fiercely protective of Lothar and his other foster son Kyle. He even threatened to cut out the hearts of the other main characters if anything happened to Lothar or Kyle because of their Inquisition work. Lothar is equally protective of his crazy mercenary family — he and Rogue nearly killed each other when Rogue refused to believe Kyle selling weapons to cultists was just a stupid mistake and threatened to kill him and Lothar's dad.
Goblins has Pan, a blind ogre, fulfilling this role for Yala, a mute, disabled kobold who acts as his 'pilot'. Threatening Yala while Pan is nearby is a good way to get yourself brutalised, as the dwarf in this strip finds out to his cost.
Even though Iratu and Sakido are demons, when they are put in danger Darius, the angel from Slightly Damned, exemplifies this trope in spades.
In the webcomic Luci Phurr's Imps , the three imps (Pain, Tears, and Misfortune/Alsadair) are devoted to happy, good little girl, Luci. But as some kids, adults, and other imps have discovered, if you threaten or upset Luci, or try to take her away from the trio... you WILL end up regretting it.
For that matter, Agatha's father Bill and her uncle Barry as well, to judge by flashbacks in both the comic and novelization. When Castle Heterodyne was wrecked and Bill's wife and children apparently dead, they embarked on a Roaring Rampage of Revenge to find and stop The Other. Given that The Other is still ''terrified'' that Barry will show up, they did a good job slowing The Other down.