Help making a jackalope

[saxavarius]

For those that don't know what a Jackalope is:
http://2.bp.blogspot.com/_JemHDK-D_3Y/TGtswu7mIvI/AAAAAAAAAMM/G77rjeWuEig/s1600/jackalope.jpg

I want to make a jackalope using the dire rabbit as a base: http://www.dandwiki.com/wiki/Dire_Rabbit_(3.5e_Creature)

I just need to add a gore attack so it feels more like a different creature and not just a rabbit with horns; the problem is I dont know what the appropriate damage dice would be. Any help would be appreciated.

[Greenish]

A humble bison (http://www.d20srd.org/srd/monsters/bison.htm) has the equally humble 1d8, but to really capture the awesome power of a jackalope, the 2d6 (and double damage on charge) of the rhinoceros (http://www.d20srd.org/srd/monsters/rhinoceros.htm) is obviously called for.

[rot42]

Chapter 5 in the Monster Manual covers stuff like this, with the suggested damage table being on page 296. Greenish gives good advice.

[saxavarius]

Thanks
Might not give double damage on a charge, i want this for a druid's AC/mount and don't want DMGs thrown at me.