The largest UK the Great Tit – green and yellow with a striking glossy black head with white cheeks and a distinctive two-syllable song. It is a woodland bird which has readily adapted to man-made habitats to become a familiar garden visitor. It can be quite aggressive at a birdtable, fighting off smaller tits. ! https://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Great_tit_side-on.jpg/800px-Great_tit_side-on.jpg!
In winter it joins with the blue tits.