Very much like how we have rare monster spawns such as love puppies and soul jellies, perhaps we should have a random chance for a boss we come up against to be altered slightly.

All boss monsters would be standard on difficulties lower than Elite, and on elite every time a boss is encountered it has a rare chance to have an alteration that may change a player's tactic. These bosses are conceptualized below:

Snarbolax
The supreme stalker of the gloaming wildwoods has company with other beasts. Now we get to meet them!

Vog Cub and/or Skolver
Both other large beast names come to mind, such as a mighty skolver or a vog cub. These bosses would take heavily reduced damage VS all damage types and have attack patterns similar to the Snarbolax (with their status piled on top of it). When stunned by the beast bell, the beast bosses would take damage similar to how the Snarbolax takes damage, maybe slightly less due to the lack of impenetrable armor.

Alpha Snarbolax
For a new special form, have an alpha Snarbolax. This would act like a standard snarbolax, except every time it was stunned, it would burrow away and two alpha wolvers would come into play and fight for the snarbolax. After killing both alpha wolvers, the snarbolax will come back, in the center of the arena, do its battle cry (without its armor on, mind you) before burrowing into the ground. After it burrows it would regain its armor and the cycle would restart.

Royal Jelly
One of the biggest flaws in the Royal Jelly's design is the fact that it's a damage sponge. To make the boss fight fresher, we need to negate the sponge-ness of the giant slime...

Royal Jelly Heir and Assassin
A jelly assassin has murdered the previous Royal Jelly, forcing the heir to the throne! In this arena, the heir and the assassin spawn in different parts of the room (top left and top right), and are about half the size of the Royal Jelly each. The assassin can use the spin attack immediately and takes less damage from shadow damage, but is also less resistant to piercing damage. The assassin has as much health as the first two phases of the normal Royal Jelly, and cannot heal.
The Royal Heir, on the other hand, has spikes. Eek! This monster has a ranged attack and a little less health than the assassin, but has the same defenses as the Royal Jelly itself. The Heir has two phases, one with an oversized crown and spike attacks, and one where the crown breaks and it uses its rage attack, shooting spikes out of its core as it flies. This heir can heal, but only from polyp spikes.

Royal Lichen Colony
A large lichen colony that acts as an oversized giant lichen colony. This enemy will split in two every time each one is killed, resulting in a reverse lichen colony process. The royal lichen colony will split into two royal giant lichen colonies, which split into two lichen colonies, and etc. These lichens cannot combine into a larger colony after split, and none can be healed.

Roarmulus Twins
The Twins are a fun and frustrating fight. Let's make them more interesting! Each twin has a different number generator on it, so you can have a normal twin and a new twin! They don't have to be identical twins!

Trojan Twin
This Twin is neutral to all damage types, but houses a special trick! Whenever the monster is downed from a teammate's rocket, it will release 1-2 gremlin thwackers from its gaping mouth. When this twin goes down, it stays down from twice as long. This twin also loses the ability to use the phase 3 laser - instead it will "down itself", sending out a shockwave that stuns players and scuttlebots hit by the blast (think tortodrone smash), and release 1 darkfang thwacker.
This mutation has a more earthy color in appearance.

Alchemized Twin
This Twin as been tinkered with to match our alchemizer guns! When its rockets collide with another twin's rockets, these rockets are redirected in a random direction. When rockets hit the twin's shield (after it has been damaged enough but the other twin hasn't), they will reflect back towards the nearest knight, at an angle. This Twin also looses its laser attack, instead favoring three consecutive tracking rockets (tier 3 rocket puppy) that also inflict shock.
The scuttlebot spawns on this twin's side of the playing field disappear once the game begins and after one scuttlebot has spawned there.

Love Twin and Empathy
This is a long shot, but I still wanted to throw it out here: A giant love puppy! This love puppy has eyes only for its Twin "Empathy", and will never shoot rockets at it. It will instead shoot healing hearts that collide with rockets to create a small heart explosion that can heal knights, although the standard healing projectiles will harm knights. When these hearts collide with Empathy, they heal both twins. The only exception to this is if both twins are at full health, in which case if a heart hits the other twin, both the twins will down themselves. The love twin has twice as much health as a regular twin for each phase, but when it is on the field the other twin does NOT have to be harmed to have it switch phases. The second twin is named "Empathy" for as the Love Twin is hurt between phases, empathy will match Love Twin's phases.
Love Twin and Empathy both still have lasers.

Vanaduke
Ahh, the big one. We need to make this fight fresh...

Freezer Burn Vanaduke
Vanaduke has been sitting in the freezer too long, and now holds up a freeze-themed battle! The orbs around Vanaduke are a mixture of freeze and fire orbs, and Vanaduke's mace will sometimes inflict freeze instead of fire. Shadow fire still falls from the ceiling, but snow clumps (the things that slow us down) will also fall from the ceiling. This version of Vanaduke is immune to freeze (duh), so tactics will have to change! This version of Vanaduke cannot use the dash attack, however he can use a freeze version of the flamethrower attack at phase 2.

Warlord Vanaduke
This variant of Vanaduke will summon minions to fight for him more frequently than others, and gains and ability to do a double smash with his mace. This double smash smashes first in front of him, delays a moment, then smashes behind him (Alternatively, send a shockwave out from behind Vanaduke that will stun and damage any player behind him). This version of Vanaduke has less orbiting balls of fire (1 on phase 3, 2 on phase 5) and is neutral to all forms of damage, including shadow damage at phase 5.

Remember, these boss alterations only appear on elite difficulty, and very rarely. These are intended to freshen up boss runs for players who do a lot of them and have succumbed to the routine of killing each boss using one method. Defeating these special bosses can reward extra boss tokens, a special material for reskinned gear (perhaps that can be crafted at the sanctuary alchemy machine, or a new alchemy machine at the core), or a extra loot boxes after the battle.

If you have interesting boss ideas, go ahead and leave more here! For each boss, try to think of fair fights while changing up how we fight things. Royal Jelly should not be dealing curse and only take damage from normal weapons without a really good explanation and a constant source of normal damage. If you think one of my ideas can be built upon more, please feel free to do so! I'd love to hear what you all think of these.

ACK, double posted this topic! Graveyard!