Have you ever gone digging through a trademark site? I did, and I found a couple of really interesting ones.
Hasbro's Battle Beasts Trademark, filed 4/23/1987
Diamond Select Toys' Battle Beasts Trademark, filed 10/6/2008
Of the Diamond one, it says that it will cover such diverse ranges as: "Games and playthings, namely, board games, action figures, toy vehicles, electronic educational game machines for children, playing cards, card games, balls for games and sports, scale model vehicles, toy vehicles and radio-controlled scaled vehicles"
The most fascinating thing to me, though, is that this means they've had the brand since 2008. The first Diamond Select Toys Battle Beasts item was a promotional Minimates figure, given away in February 2010. I had no idea they've had it for so long!