There are two kinds of Bot Spawners in SMNC, Spawns for Lane bots, and Spawns for Exterminator Bots.
Lane bots spawn from two gates near the money ball, here, additional Fujis can be bought, coming with two Scramblers, and for $4000, you can buy a JackBot XL, the walking, talking piggy-bank o' pain.
Fujis: Fujis are Round, floating bots that can take alot of punishment, especially early on in a match, they can often lead the push that can bring down a turret, and will certainly get a turrets shield down unless concentrate don by multiple Pros early on. Late game they become less useful, but can still take punishment. They shoot slow moving, large, team-coloured Orbs that deal moderate damage when they hit. I'd suggest buying these and escorting them early on when you can. Fujis, when bought come with two Scrambler bots, Scramblers head towards enemies and Silence them, making then unable to use Skills, Alt-Fires or Grapples. Capitalise on a silenced pro buy killing them before they get out of the Scramblers range and escape.
JackBot XL: The JackBot XL is the largest bot SMNC has to offer, it has extremely hard hitting cannons on both hands and it can ground slam when an enemy Pro approaches. It has a humongous health pool and can take alot of punishment. However, they can be grappled and teamwork will easily take a Jackbot down, wasting your $4000. Thankfully, if a Jackbot is escorted, preferably by a Support to heal it, and a Cheston to use Bananas to break grapples on it, it can take down a turret or two before it gets taken down.
Exterminator Bots are bots that will chase down and attack enemy Pros, their spawners can often be found near the middle of the map. Two kinds of Exterminator bots are available:
Bouncers: Bouncers are large, gorilla-like bots that will chase and grapple enemy pros, like Pro's Grapples, their grapples can be avoided by jumping, although this will result into them charging into you and knocking you back, they can also punch Pros, dealing heavy damage. If you purchase a Bouncer, be sure to capitalise on any grapples they get buy attacking the immobile enemy. Kills from the Bouncer give cash to the player who bought it.
BlackJacks: These are walking bots that, like Shady-bots, have a Spiked fist on one hand and a Slim-bot like laser on the other hand. They have decent movement speed, but die quickly, although their melee attacks can do alot of damage and send pros flying. They cost only $500, but you're better of buying a Fuji wave, as Blackjacks are easily killed and relatively weak.