Spike and Tyke are American cartoon characters from the Tom and Jerry animated film series, created by William Hanna and Joseph Barbera. Spike (who goes by different names in a few shorts – Killer for four shorts, Butch for two shorts, and Bulldog for one) is portrayed as an English Bulldog, who is generally amiable and friendly, and a loving father to his son Tyke in several cartoons. However, Spike's character also has a very stern and fierce side for occasions, such as when he is defending his son Tyke.

Spike made his early appearance as an unnamed Bulldog in the 1942 Tom and Jerry cartoon Dog Trouble, and his first appearance and his first speaking role was in The Bodyguard (1944), where he was voiced by Billy Bletcher. Spike was voiced by Bletcher until 1949, from which point he was voiced by Patrick McGeehan, Jerry Mann, Bob Shamrock, John Brown, Stan Freberg, and Daws Butler, with a thick New Yorker accent similar to Jimmy Durante's.

Following Dog Trouble, Spike appeared solo as a guest in Tom and Jerry cartoons for several years, and his son Tyke was introduced in 1949 in Love That Pup.

Tyke is a sweet, happy, and innocent puppy who remains silent in most of the earlier cartoons. Spike and Tyke's characters, provide a model of father and son behavior, with Spike spending much of his free time taking Tyke on father-son outings, teaching him the facts of life for dogs and guarding him diligently when they are sleeping. In Tom and Jerry Kids, Tyke has a speaking role for the first time, aside from traditional dog noises he expressed in the prior films.

Spike’s relationships with Tom and Jerry have changed over time, but essentially, Spike has little affection for Tom Cat, who consistently disrupts his life, causes trouble, antagonizes Tyke, or does all of the above. The Truce Hurts (1948), Pet Peeve (1954) and Hic-Cup Pup (1954) are so far the only cartoons where Spike actually cares about and shows affection for Tom; these relationships often dissolve and usually end with them fighting. Tom does not usually antagonize Spike intentionally, but Spike often ends up in the middle of a Tom and Jerry chase, (as they are all seemingly living together) which ends up waking Spike up, ruining his new dog house, wrecking his and Tyke's picnic, and so on. Spike has a few weaknesses that Tom tries to capitalize upon: his possessiveness about his bone and his ticklishness.

Spike's fiercest behavior is reserved for anyone who interferes with Tyke, but also, Spike's generally well-intentioned brain is at times easily outwitted by Tom and/or Jerry. Jerry also arranges to get Tom in trouble with Spike, provoking a chase, and/or a pounding from the bulldog, and Spike will keep Tom's attention off Jerry for a while. Several stories also have Jerry taking advantage of Spike and Tyke's size and proximity, as he often tries to hide or sleep with or near Spike and Tyke for protection.

In his early appearance, Dog Trouble, Spike as an unnamed Bulldog is the main antagonist, chasing and attacking both Tom and Jerry on sight, even trying to eat Jerry, which forced the two to work together to defeat him. However, in his second appearance The Bodyguard, after Jerry willingly saved him from being poached, he became Jerry's protector whenever needed. In all subsequent shorts, Spike becomes typecast as the stereotypical dumb brute who is always duped into becoming a shield for Jerry from Tom. It is only in two shorts where Jerry gets Spike out of a jam and the dog willingly protects him from Tom in well-earned gratitude (The Bodyguard and Fit to Be Tied). On most occasions, Jerry causes trouble for Tom by luring him near Spike and harming him to get him angry, and in some cartoons, when it's perfectly obvious that Tom is not responsible, as seen in The Invisible Mouse, Spike still blames Tom and hurts him instead of Jerry. Only on one occasion does Jerry fail to frame Tom, in Hic-Cup Pup, where Tom unintentionally cures Spike and Tyke's hiccups, and Spike shakes Tom's hand.

Spike, however, is not without a softer and sympathetic side: in the short Pet Peeve, after believing that Tom is willing to leave the house in Spike's favour, Spike feels sorry for him to the point that he offers to leave instead, which Spike does until he realizes that Tom is only using reverse psychology to trick him into leaving. In The Truce Hurts, Spike is portrayed as a very intelligent and equilibrated character when he convinces Tom and Jerry to stop the fighting among the three of them and sign a Peace Treaty, but their newfound friendship comes to an end when they argue over how to share a big steak, symbolised when Spike tears the truce contract to shreds and they go back to fighting again after Tom accidentally threw the steak into the sewer drain. From the 1944 cartoon The Bodyguard to 1948 cartoon Heavenly Puss, he was voiced by Billy Bletcher. His first name is Bulldog in Dog Trouble, His name also varies in some shorts: in Puttin' on the Dog, Solid Serenade and Cat Fishin' he is named "Killer", and in The Truce Hurts he signs his name "Butch" on the treaty peace paper. He is also a Devil Dog in Heavenly Puss.