Spike the Bulldog is the deuteragonist of the American animated franchise, Tom and Jerry. Though he is usually a protector of sorts towards Jerry Mouse, his son Tyke and sometimes Tom, such as in "The Truce Hurts", sometimes going as far as being an enforcer of sorts to the mischievous rodent.
However, there is no denying that Spike is often cruel towards Tom (a stereotype of dog/cat rivalry) and although he often gives Tom several chances to avoid his wrath, he will attack the cat viciously once those chances have been spent.
Tom often tries to get revenge on Spike, so it can be argued that Spike can play both the good guy and the bad guy depending on the cartoon, let Tom and Jerry themselves who can have their share of anti-heroic or villainous tendencies on occasions in hence their two-sided rivalry. In general though, he is a bully in regards to Tom and threatens to harm the cat physically, to the point of making Tom fear for his life on numerous occasions. Although he is considered as supposedly one of the series' "protagonists", he is usually portrayed as an unfair, mean-spirited, rude, violent, selfish, reckless, egotistical and hypocritical character.
Spike can also be friendly when he wants to be and is seen to be a caring father, showing that, although a fierce opponent, he isn't entirely without merit, even if his caring moments toward anyone other than his son are extremely rare. Ironically, despite their close friendship nowadays, in early appearances Spike was an enemy of both Tom and Jerry, with the cat and mouse occasionally teaming up to rid themselves of the aggressive beast, as even shown in other episodes as well: This element of Spike seems to have faded over time as he is now considered primarily as the show's most malicious antagonist, as he is shown to antagonize both Tom and even Jerry whether if it's justified or not. In the Tom and Jerry Show in the 1980s, Spike was sometimes the rival to a basset hound called Droopy, another MGM creation.
In Tom and Jerry Kids, his personality is softer, but his animosity with Tom as a kid (or Tom's Child) still existed as he threatens Tom.
Many appearances consist of him threatening and sadistically harassing Tom despite either never being provoked or not even being his fault, even to the point of making the poor cat fear for his life.
In several episodes, he also even enslaves Tom (with Jerry joining the party).
He even antagonizes Droopy in The Tom and Jerry Comedy Show. (sometimes teaming up with The Wolf).
In his first appearance "Dog Trouble" and several other episodes, he is shown to also antagonize Jerry, forcing the cat and mouse duo teaming up to fight back. In this short, he not only chases after Tom, but also after Jerry, and without contempt for the fact he is intruding Mammy Two-Shoes' house.
In "Pet Peeve", he tries to capture Jerry and competes with Tom in this. (Both get kicked out of the house anyways.)
In "The Truce Hurts", let alone harrasing Tom as usual, it's one of the episodes where he eats Jerry, yet tries to have all the steak to himself. (In fairness Spike, Tom, and Jerry all fought for it. All three, return to their respective enemies).
In "Heavenly Puss", he is portrayed as a devil dog and lives in hell, where he manipulates Tom to be sent to hell so that he can torment him in boiling hot water.
In "More Powers to You", Spike is a super villain in this episode known as "Doom Dog", who the newly empowered Tom and Jerry team up to beat.
He was at his worst in the 2014 TV series, as he became an annoying jerk that would not only hurt Tom, but Jerry as well, even when it is usually undeserved:
In "Tom-Fu", he is depicted as a passive-aggressive bully to Tom on a new level, with Jerry and Tuffy joining the party. Forcing Tom to practice kung-fu as self-defense to stand up for himself.
He would often lack responsibility for his actions and blame Tom and Jerry for being rude, violent, and unfair despite possessing these traits himself.
In "Duck, Duck, Loose", he beats up Tom even when he was asleep despite that Quacker accidentally sleepwalked into Tom's mouth.
Often takes advantage of Tom and Jerry for personal gain, such as for defense means and as decoys. Such as a pillow and punching bag to terrorize Tom in "One-Way Cricket".
Falsely accuses Tom for being responsible of the balloon incident and floats him in the air which caused him (alongside Jerry and Tuffy) to accidentally ruin part of Rick and Ginger's anniversary celebration in "Balloonatics".
Bulldozes a bunch of trees (including the squirrel's home) to build a freeway in "Triple Trouble".
Steals Toodles Galore from Tom and cheats his way to the space race victory in "Spaced Out Cat".
In "Jackhammered Cat", Spike guards a feast into which both Tom and Jerry stumble upon and are hoping to have some to their dismay of starvation. At the end, he takes advantage of it all being taken by the construction workers only to chase after Tom and Jerry and have them eaten alive.
Chases after Tom and attempts to eat him as a "dogfish" in "Catfish Follies".
In the episode "Feeding Time", he tells Tom to not feed the animals or else he'll get fired.
In Tom and Jerry: The Magic Ring, he and Tyke sadistically harass and beat up Tom despite never being provoked, then joins Butch Dog and Butch Cat along with his son to antagonize Tom throughout.
In Tom and Jerry: Shiver Me Whiskers, he scares Jerry to death by shortly attempting to eat him, then attempts to steal the map to the Treasure of the Spanish Mane to himself. He successfully took advantage of Jerry for it, until Tom successfully managed to grab it by surprise. He thus enslaves Tom by the end as he takes full control of him after yet another accidental land.
In Tom and Jerry: Blast Off to Mars, he terrorizes Tom and the whole town by repairing the Invincatron as he didn't even bother to sacrifice his bone to the fact that the town was in danger.
In Tom and Jerry: The Fast and the Furry, he blindly harasses Tom by beating him and even choking him to death, which adds insult to injury onto the amount of destruction already caused onto Tom and Jerry's property. He then gets away with it all and has Tom framed for all of it despite being left in charge by his owner for an hour to take care of their home. Unlike the previous mentioned films however, Spike does fortunately end up getting his comeuppance as Tom's car lands on him, making the poor cat safe from another form of harassment that is otherwise lead by an accident that, as usual, wasn't Tom's fault to begin with.
In Tom and Jerry: Willy Wonka and the Chocolate Factory, he assists Arthur Slugworth to obtain the Everlasting Gobstobber as the secondary antagonist and beat Willy Wonka in the candy-making business. At the end, he and Slugworth both get their comeuppance as they both get shrunk by Tom.
In the Game Boy Advance game Tom and Jerry: Infurnal Escape, he imprisons and enslaves Tom in a boot camp, and even kidnaps Toodles Galore to eat her. As Tom comes to the rescue with support from his girlfriend and Jerry, is being threatened to be sent to hell so that he can torment him in boiling hot water.
In the Sega Mega Drive/Genesis game Tom and Jerry: Frantic Antics, he appears as an obstacle to prevent Tom from reaching home, even from rescuing Jerry as their house breaks apart.
No more funny business.
I'm gonna skin you alive.
~ Spike to Tom
Listen, pussy cat, if I catch you bothering my boy again, I'll tear you apart! Now beat it!
~ Spike to Tom after Jerry makes him in trouble while watching Tyke.
There's gonna be trouble!
Wait a minute pussy cat, ever since I was a pup I wanna a little place on my own and I still want it, but if one more thing happens to my little dream house, THERE'S GOING TO BE MURDER!
~ Spike after Tom hits him and his dream house
Listen pussy cat, he's clean now, and he better be clean when I get back! And if he ain't, I'll tear you limb from limb, understand?
~ Spike when Tom pushes Tyke in the mud
That's my boy.
~ Spike to Tyke Bulldog.
Listen pussy cat, My boy is learning how to chase cats, and I Do want him to have any trouble. Understand? When he starts barkin', you start climbin'. Is that clear?