Thought I'd bring back Vibe Check- mainly because she's adorable, but also because I wanted to add a little to her personality.
Yes, her cutie mark is a hand grenade,that is canon to my AU. I originally used it because I found it amusing, but it grew on me rapidly, and it relates to how she has a rather unfortunate tendency to butt into conversations this does NOT make her popular with griffins in particular, and in their case, tends to result in a situation that can be likened to dropping a live grenade into a oil drum filled with napalm.
Spicy XD
Of course, as my AU involves humans, it wasn't until humans began filtering into Equestria that anypony had any idea of what a hand grenade even was. Vibe Check bears the mark with good humour and a smile, and the implications aren't lost on her.