Heavy Shells

"Heavy shells do extra damage to Ceramic, Lead, all Fortified, and all stunned bloons. Can also pop Black Bloons."

- In-game description

 is the third upgrade of Path 2 for the Mortar Monkey in Bloons TD 6. It allows the mortar to pop Black Bloon properties as well as deal +1 damage to all Fortified, +1 damage to all Leads (including visible DDTs), +3 damage to Ceramic Bloons, +1 damage to MOAB-class, and +2 damage to stunned bloons.

It costs $765 on Easy, $900 on Medium, $970 on Hard, and $1,080 on Impoppable.

Appearance
With the Heavy Shells upgrade, it changes the appearance of both the monkey and the mortar cannon. The monkey is now an officer in a green military-style shirt and green beret, paired with a black-barreled mortar cannon with two yellow stripes around it. The monkey stands by its barrel to continually press buttons on its handheld remote, instead of pushing a ground-level lever. In the official artwork, the monkey points with its left index finger.

Costs

 * Updated as of Version 29.4

Summary
Heavy Shells is quite expensive for a single tower with moderately slow attack speed and low accuracy, but it becomes a good low-cost option at countering early Ceramics, as well as good support at destroying groups of Black Bloon layers in earlier rounds. In addition, it has a unique synergy with stun attacks by dealing more damage to bloons inflicted by a stun status effect. Similar to most Mortar Monkeys, targeting Heavy Shells along bends will optimize the accuracy of its explosive attacks.

Heavy Shells is usually a stepping stone to Artillery Battery in most cases, but it does a good job as a stepping stone compared to other upgrade alternatives, due to being able to damage any non-camo bloon type, having global range potential, and possessing decent pierce.

Tips

 * Since Burny Stuff no longer can apply napalm onto Black Bloons without support from MIB or similar, Heavy Shells is required if wanting to pop Black Bloons with a Mortar Monkey.
 * This is a rather low-cost upgrade that can be used to reliably break down early Ceramic Bloons into easy-to-pop chunks.
 * There are certain attacks that can stun bloons, which in turn will trigger the extra damage to stunned bloons from Heavy Shells.
 * These include but are not limited to:
 * Bloons only: Shell Shock, Bloon Impact, Flash Bomb.
 * Blimps only: Maim MOAB, Cripple MOAB.
 * All: Pop and Awe ability, Bloon Crush, Tsar Bomba ability, Admiral Brickell's Mega Mine ability against surviving targets, the Vine Rupture ability (MK only) from Spirit of the Forest, Cave Monkey, the lotuses on Lotus Island, Rocket Storm with the Gorgon Storm MK active.
 * When it comes to maximizing the extra stun damage, the best options to pair with include Bloon Impact and Shell Shock versus bloons or Maim MOAB versus MOAB-class bloons.
 * The best crosspath for Heavy Shells is 2-3-0. Heavy Shells benefits better from the increased damage given by the Bloon Buster upgrade. There is little need to add Burny Stuff because Heavy Shells already reliably pop Black Bloons, and Increased Accuracy is not as helpful as Bigger Blast due to the fact that Heavy Shells already has a decent attack speed.

Trivia

 * There is used to be a bug where a 0-3-2 Mortar Monkey could not apply napalm to Black Bloons despite the Heavy Shells upgrade allowing to pop Black Bloons. This was fixed on Version 7.0; Black Bloons popped by a 0-3-2 Mortar Monkey will now turn into Pink Bloons with the Burny Stuff effect instead of without the Burny Stuff effect.
 * Prior to Version 17.0, the description was "Heavy shells do extra damage to Ceramic, Lead, and all Fortified Bloons. Can also pop Black Bloons." but was changed because of the added bonus stunned bloon damage mechanic.
 * Heavy Shells and its subsequent upgrades were formerly the only towers to specifically deal extra damage to Lead Bloons, until Lead to Gold and its further upgrades received a lead damage buff in Version 23.0.
 * However, a submerged 4-2-0 Monkey Sub does +1 damage to Leads since Version 18.0.
 * Heavy Shells and its subsequent upgrades were formerly the only towers to deal more damage to stunned bloons, but this is no longer the case after Sauda was released; her Level 6+ upgrade allows her to deal more damage to stunned bloons.