Hey everyone!

I was planning a campaign for my friends to participate in across the upcoming uni year (6 players) and decided that I wanted a slime boss for my dungeon so decided to make one! Let me know what you think about it, any changes you may make and some grips you have with the design! It's made to be an earlier threat to the players.

Stat Block

Slime Boss

Slime Boss Large ooze, chaotic evil

Armor Class 14 

Hit Points 180 (24d10 + 36)

Speed 20 ft.

STR 16 (+3) DEX 7 (-2) CON 14 (+2) INT 7 (-2) WIS 10 (+0) CHA 4 (-3)

Saving Throws Strength +5, Constitution +4

Skills Perception +2, Intimidation +5

Damage Immunities - Poison Damage

Vulnerabilities - Fire damage

Condition Immunities - Poisoned

Senses - Passive Perception 12

Languages - Understands Common but cannot speak

Challenge 5 (1,800 XP)

Proficiency Bonus +3

TRAITS

Gloop Lock. When a creature hits the Slime Boss with a melee attack, the attacker must succeed on a DC 14 Strength saving throw or have disadvantage on their next attack roll.

Slime Summon (Recharge 5-6). The Slime Boss can lose 15 hit points to summon two Mini Slimes in unoccupied spaces within 10 feet. The Mini Slimes act on the same initiative count as the Slime Boss and obey its commands.

ACTIONS

Belch (Ranged Attack). Ranged Weapon Attack: +3 to hit, range 30 ft., one target and up to two creatures within 10 feet of it. Hit: 8 (1d8 + 3) poison damage. Each creature hit must also succeed on a DC 14 Constitution saving throw or be poisoned for 1 minute. While poisoned in this way, the creature has disadvantage on their next attack roll.

Bite (Melee Attack). Slime Boss Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) piercing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

I'm not really seeing the slime in the slime boss. You might want to change some of its attacks to be more like other oozes. Also, from flavor standpoint, I don't understand Gloop Lock. What is it doing? I think that one should be changed so that the weapon gets stuck to the slime.

Initially I thought this enemy was undeserving of as low of a CR as it has until I noticed that Gloop lock doesn't actually disarm enemies. Maybe make it able to disarm players and add resistance or flat out immunity to bludgeoning from non-magical sources. Other than that it seems like a cool enemy. 

I see what you mean, I’ll definitely change a couple things to make it feel more slimey! 
for gloop lock, I simply wanted a cool passive that tied into the gloopy and slimey nature, but overtime realised that it’s worded quite weirdly and had a tough time describing how it looked to the players in a one shot. 
i really like the idea of the weapon getting stuck! I think it’ll work better than what I have currently

thanks sm for the feedback! 

Quote from Chromafield >>

Initially I thought this enemy was undeserving of as low of a CR as it has until I noticed that Gloop lock doesn't actually disarm enemies. Maybe make it able to disarm players and add resistance or flat out immunity to bludgeoning from non-magical sources. Other than that it seems like a cool enemy. 

 Oooo yes I like the idea of immunity to bludgeoning, it works quite well with the image in my head haha! 
disarming seems like a better idea than what I’ve got so I’ll definitely have a look back at tbat

thanks so much for the feedback!