He looks like the member of the Get Along Gang that no one ever talks about. How about Boomer? :)

Boomer it is, Thanks!

Although somehow I don't think that grenade is live, any more.

Boomer's weapons of choice tend to be art materials, Photoshop Elements and occasionally, Windows Troub...erm Movie Maker. )

He could be described as long standing friend and ally of The Gang rather than an actual member. Dog alone knows they need all the friends they can get these days...

What kind of grenade is that?

It's a paint bomb that works in a similar way to a soda-acid fire extinguisher. Rex doesn't do Hi-Ex. (He may be eccentric but he's not insane.) Food grade, naturally, not dissimilar to the stuff they used in that Sony Bravia advert a couple of years back...(I think it's on YouTube, if you care to look. )

Don't play with your ordnance.