Minecraft Dungeons

Requires DLC to unlock
Abomination Roar is the level 16 reward on the free track of the Season 2 (Luminous Night) Adventure Pass.

Complete daily trials/weekly challenges or Tower runs to level up the pass and claim the emote.
Probably the fastest way to gain XP for the Adventure Pass is to abuse cloud saves on the top floor of the Tower.
See the Golden Gauntlet achievement solution by @Palesius if you need help figuring out how to do that.

Then you must use the emote when fighting the Jungle Abomination boss on the Overgrown Temple level.
You may need to finish defeating the boss/exiting the level for the achievement to pop.
This mission is only available if you've purchased the Jungle Awakens DLC.

Miscellaneous info:
-Use the and bumpers on your controller to switch between the seasons when looking at the Adventure Hub.
-Default controller input for emotes is
-To equip the emote, press then to cosmetics page.

For this achievement you will first need to have the Jungle Awakening DLC and you must also be rank 16 on the Luminous Night Adventure Pass which is season 2. Once you have both of these make sure you claim the free reward "Abomination Roar" emote at level 16. (You can check your level by going to the "Adventure Hub" totem in your camp).

Now you need to make sure the emote is equiped to your character. You can do this by pressing and then by pressing until you get the the cosmetics page. Go down to your emotes until you find the Abomination Roar and then equip it by pressing .

Now go to the Mission Select table in your camp and start the mission "Overgrown Temple" this will be the final mission that you unlock as part of the Jungle Awakening DLC. This achievement can be done on any difficulty so it doesn't matter which you chose. Now progress through the level until you get to the final boss. You will know you are close as the final objective in the top right corner will say "Reach the sun room, abolish the Abomination"

Once you reach the final room and the boss spawns in. All you need to do is press for your character to emote. Once this is done the achievement will unlock for you, some players have said that it doesn't give them the achievement right away so it may be possible that you need to complete the level if the achievement doesn't unlock, but this is very simple as there is only one more area afterwards.

Update: Afaik the non-DLC way is currently not available due to the new tower. I'll edit the solution when I notice that the tower has a Jungle Abomination again.

Since all the other solutions claim that the DLC is required I decided to make this an own guide. Comments under the top solution have already pointed to this achievement unlocking in the tower if you get the Jungle Abomination as the end boss.

DLC NOT required (currently), which is probably why this is listed under the Title Update instead of Addon.
This week's tower (2023-9-3 to 2023-9-9) does have a Jungle Abomination as end boss at level 14.
That means that players that don't own the DLC can unlock this achievement.

1. Unlock the emote "abomination roar" as the reward for reaching level 16 in Season 2 (Luminous Night).
2. Equip the emote before entering the tower by hitting on the d-pad and pressing until you are in the Cosmetics menu to the very right. Under Emote select "Abomination Roar".
3. You cannot change your emote while in the tower. If you have started the tower run before selecting the proper emote you can exit the tower at the end of each combat level using the totem.
4. Start a tower run. Difficulty level doesn't matter, so I suggest doing it on Default difficulty unless you're going for the difficulty specific achievements mentioned above at the same time. Press to change difficulty.
5. Carefully advance up the tower until you're at level 14.
6. As soon as the boss spawns you can use your emote by hitting on the d-pad.
Done!