It certainly looks to me as if Beastie is a stray, or as someone else said on here, if Beastie has owners she/he needs new ones !. The lump on the side certainly looks like matted fur, can you feel the lump, you can tell if it is fur or if it is anything else you need to take Beastie to the vets (call the vets first and explain the situation). I have a white cat who is grubby from going outside but not as grubby as Beastie so my guess would be that Beastie is outside 24/7. If you are feeding Beatie Ham make sure you provide a bowl of clean water as well as Ham is quite salty, you might want to get a bag of Economy Complete cat food from Tesco, it is only about £1.20 for a massive bag (will last one cat at least two weeks) which would be a lot cheaper than you giving Beastie ham. Well done on looking after Beastie. Also on another note you will need to get Beastie checked at somepoint for FIV etc etc. Good Luck.