Skullgrin, Bomb-Burst, Landmine and Snarler are all '88 Pretenders.
Here are some pictorial example of 1989 Pretenders:
Bludgeon
Stranglehold
Octopunch
Thunderwing
Longtooth
Doubleheader
...as you can see the 1989 Pretender robots don't suffer from being all lanky and anorexic like the 1988 Pretenders. They also have better looking alt modes too. A lot of the '88 Pretenders transform into ambiguous looking "WTH?!" alt modes, whereas the '89 Pretenders' alt modes are instantly recognisable. e.g. when you look at Bludgeon's alt mode it is undeniably a tank. Compare this with say Waverider's alt mode... that's meant to be a submersible?! I got that toy for my birthday in 1988 and I just played with it as a jet. It was only later when I read the tech specs that I found out it was meant to be a sub. And even in G1 canon there was at least one moment where Waverider's alt mode was portrayed as a jet ("On The Edge of Extinction")... that shows you how ill-defined the 1988 Pretenders' alt modes were; even official canon sometimes didn't know what the hell they were meant to be! :p
I like the concept of Pretenders. They weren't terribly well executed in 1988, but they got better in 1989 (and cheaper too! :D).
IMO the best Pretender toy made was Bumblebee. No other Pretender robot toy impresses me as much as Bumblebee. The alt mode is clearly a VW Beetle and in many ways - unlike the other Classic Pretenders, Bumblebee is arguably an improvement over his predecessors. Unlike 1984 Bumblebee his Beetle mode isn't super-deformed - neither is Goldbug's, but of course, Pretender Bumblebee has more articulation than either '84 Bumblebee and Goldbug (although having more articulation than a Throttlebot isn't hard ;))
http://i6.photobucket.com/albums/y22...lscream013.jpg