I need help coming up with a gifted ability to give a chaotic neutral character

In my campaign, each player was given a over-powered legendary ability, the granting of which takes the form of a spiritual companion (they are pacific, can't fight) they can call upon. Let me give you a summary of a few of them before I raise my problem...

Half orc barbarian was easy, he wants to be a guardian for his friends but feels he's failed in that area to many times. So his ability is that, for a period of time, he takes all damage dealt to allies within 20 feet and has resistance to all damage. His companion is a bear, a gentle protectorate to what it loves, and fearsome killer to any that threatens.

half-elf Druid was fun, too. When we first started, she would tell stories about the first time she ever went bear-form and wrecked shop, taking out sooooo many enemies. So it was kind of disappointing for her when she realized that this didn't work past like level 3. So when she chose a sparrow, I said that the sparrow granted her wisdom and insight into the moving, breathing things of the world and she can temporarily make her beast form CR equal to her druid level (oh, gods of balance have mercy on me, but she was so happy, the look on her face was fantastic).

human fighter messes up a lot and can never seem to make things work, magnified by feelings of inadequacy being continuously compared to his brother. But he gets back up each time and recently had some victory in that realm, so his companion, a gilded armadillo lizard, grants resilience and fortitude, allowing him to be completely impossible to move for 18 seconds.

Now my problem. That's just a few, the party is stupid large. But I can not figure out what to do with the chaotic neutral cleric. The guy who plays him is hilarious and the source of each gut-busting laugh we endure. He chose a chicken for his companion, which, again, is perfect, but I just can't think of an ability which is up to par on the fun-factor scale (which is super important to me) and which matches his chaotic, trickster-esque style. I don't want to go into to much detail because he has secrets he wants to keep from the party and some might read this, so PM me if you want to help but need more details.