If you thought that being able to play as a talking gorilla scientist who wields a Tesla cannon and wears a jetpack was stretching reality a bit much in Overwatch, you haven't seen anything yet. As of June 28, 2018, Hammond, Overwatch's 28th Hero, has been added to the game. Officially called Wrecking Ball, Hammond is a giant hamster who rides in an equally giant hamster ball/mech contraption. As one may expect, Hammond can zip around the battlefield with relatively high speed when his mech is set to the hamster ball mode. Combined with the mech's built in Grappling Claw, which will enable him to grip onto the environment in a similar manner to how Widowmaker can quickly grapple to any available ledge, there is little doubt that Hammond is going to be the fastest and most maneuverable Tank in Overwatch. In case you are wondering, yes, you can kill people while in hamster ball mode.
Of course, speed is somewhat irrelevant if you can't take or deal damage, so Hammond's mech is equipped with dual sets of dual machine guns that pop up when you stop rolling around. In addition, Hammond has a personal shielding ability that gives his mech additional shielding based on how many enemies are nearby. Once Hammond's Ultimate ability is charged up, you can deploy a giant minefield that covers an area that is roughly the same size as your average capture point. While the mines themselves are rather hard to miss, the amount of time and effort that it would require to clear an area of mines without blowing up half a team is substantial enough that it can be considered a zoning Ultimate.
Naturally, you may be wondering how best to use and or fight against Hammond. While early impressions are rather varied, it appears as though the most optimal way to use Hammond is in a kind of a shock trooper role. Similar to how the Droidekas from Star Wars operate, you can roll up to a chokepoint, shield up, and then start filling the air with hitscan bullets. Then, once your team has forced an opening, you can roll through, disrupting the other team's attempts to regroup with plenty of knockback abilities and respectable headshot damage. Alternatively, you yourself can initiate a push, but without any way to protect the rest of your team, this will inevitably require at least a modicum of communication.
Unfortunately (or fortunately), Hammond doesn't have the same amount of reliable burst damage that other traditional dive tanks have, so it seems doubtful that he will be replacing D.Va or Winston on a wide scale. In addition, despite the fact that Hammond can gain a ludicrous amount of shielding (in certain cases, exceeding 1,000 total health/armor/shielding), there is no way for him to actually negate the damage taken, so there is no real disincentive not to shoot him the moment that he shows up to farm Ult charge. Consequently, Zenyatta's Discord Orbs are going to be essential to taking down Hammonds, though it will still require the combined fire of a full team to take down a fully shielded Hammond. Obviously, Heroes who are capable of dealing a massive amount of damage in a short period of time like Bastion and Hanzo are going to be able to chew through Hammond (in theory at least), as will any Hero who can control his ability usage (i.e. Sombra).
Needless to say, it is still far too early to determine whether Hammond is the most overpowered Hero ever to exist in Overwatch or another niche pick for highly skilled individuals, but so far, he seems to be quite adaptable, but not so powerful that he smothers traditional team compositions by simply existing (looking at you, Brigitte).