I found my cat two years ago as a stray kitten. He's always been on the more aggressive side, but I've never let it bother me because I know each cat has their own personality. However, I feel that it has gotten a little out of hand. One minute, he'll be laying up against me, purring and seeming fine while I pet him, but then he'll randomly fold back his ears and start biting and clawing my arm. I haven't noticed any particular spot that makes him do this, it's just at random most of the time. He is also fairly aggressive with strangers and hisses at them and sometimes tries to attack their legs. He's not, however, aggressive towards other cats. I was wondering if there's seems to be any particular reason why he may get so aggressive sometimes. Is it because he needs to play more? I leave the house fairly often for school and work and don't have much time to play with him. Is there any way to help get his aggression out without me or strangers being the target especially when I'm not home?
I've also noticed he's been throwing up more often, but the aggression has been going on before this started. I took him to the vet recently and nothing seemed to be unusual. I'm not sure if this relates at all though to the aggression.