Using rage faces in presentation I was asked to give a talk at a workshop. I plan to tell a short story, 5 - 7 minutes, about how my collaborator and I came up with the idea presented in the talk. This story would:


Give the motivation: I have this problem, and my collaborator had a solution for a (seemingly) unrelated problem.
Explain the contribution: I did this and he did that.
Explain the intuition of the solution: he said this and we recognized that etc


I think the story would be interesting, and as it involves two people, I wonder if I should use two rage faces representing my collaborator and I (yes, I often visit 9gag). 

On one hand, I think it would be funny. On the other hand, I'm afraid people may think I am not polite/unprofessional, in particular old people. The workshop is co-located with a top tier conference, and I don't want to leave any bad impression.



Update: Thanks everyone for the answers. At first, I intended to use the avatars on our homepages, but I think it's very award to keep showing my face from slide to slide. That's why I think about rage faces, the reason is that they are very simple, but emphasize the emotions very well: struggle, then confused, then surprised...

But I understand not many people like it, so I will think of other way.
TL;DR: If in doubt, leave it out. 

In talks, avoid anything that can offend or be misunderstood, especially if you do not know your audience. It is ok to make self-deprecating jokes, but you want to keep the atmosphere somewhere between serious to light (depending), but outside the sentiment of sadness or anger if you do not have political ambitions. Your "angry faces" may be funny, but never underestimate that they may be misunderstood (including people believing that you did have a fall-out with your friend in the preliminaries of this work - you would be amazed at what people can read wrongly into a throwaway remark).

Myself, I am quite happy use caricatures in talks, but spend time choosing them carefully to help to highlight the scientific point, never on a meta-level. People are busy enough trying to understand what you are doing, do not waste their brain power on issues you think are funny, but irrelevant to the matter at hand. 

But if you think something can backfire, you are probably right. If in doubt, better one caricature/clever idea less.