agree with Industrial Miner the guns, sword, lasers and all that is boring minecraft/tekkit/technic needs something different.
maybe a boot knife :-P
When jump ontop of a creature or animal it will obviously deal damage pending on what material you've equip to it.
Stone > Iron > Gold > Diamond
Pending if its mod compatible maybe > Stone > Copper or Stone > Tin or Stone > Silver and Egt.
That would be amazing if someone could do that i would use it for ddddaaaayyysss