Sure. Are there any old edition stats, or is this just from general knowledge?
Actually, there are two old edition Cave Bears. There's an AD&D Cave Bear that is smaller and weaker than the BECMI version.
The AD&D Cave Bear is neatly inbetween the AD&D Brown Bear and Polar Bear in strength:
Brown: 5+5 HD, attacks of 1-6/1-6/1-8, 9' tall.
Cave: 6+6 HD, attacks of 1-8/1-8/1-12, 12' tall.
Polar: 8+8 HD, attacks of 1-10/1-10/2-12, 14' tall.
The BECMI Cave Bear is the strongest of the regular Bears in that system, with the Polar Bear being neatly between it and the Grizzly Bear, that system's version of the Brown:
Grizzly: 5 HD, attacks of 1d8/1d8/1d10, 9' tall.
Polar: 6 HD, attacks of 1d6/1d6/1d10, 11' tall.
Cave: 7 HD, attacks of 2d4/2d4/2d6, 15' tall.
Even I'm not obsessive enough to want to convert two separate versions, so I'd be OK combining the two into one.
I'll post the original stats.