Materials:

Himalaya Dolphin Baby yarn (little more than ½ skein of main color) and 4.0 mm crochet hook
YarnArt Jeans yarn (yellow) and 2.0 mm crochet hook
Some embroidery floss or YarnArt Jeans yarn for nose and whiskers
8-10 mm safety eyes
Sewing needle and scissors
Fiberfill

Abbreviations:
R = row
mc = magic circle (magic ring)
ch =chain
st = stitch
sl st = slip stitch
sc = single crochet
inc = 2 sc in the next stitch
dec = single crochet 2 stitches together
(12) = number of stitches you should have at the end of the round/row
(…)*6 = repeat whatever is between the brackets the number of times stated

Arms (make 2);
R 1: 7 sc in mc (7)
R 2-3: 7 sc (2 rows)
Sl st, fold top of arm flat and 3 sc through both sides across.
F.o.

Legs (make 2);
R 1: 6 sc in mc (6)
R 2: (1 sc, inc)*3 (9)
R 3: 9 sc
Sl st, fold top of leg flat and 4 sc through both sides across.
F.o.

Ears (make 2);
For mouse:
R 1: 7 sc in mc (7)
R 2: (inc)7 (14) R 3: (1 sc, inc)7 (21)
Sl st.

For cat:
R 1: 5 sc in mc (5)
R 2: (inc)5 (10) R 3: 10 sc R 4: (4 sc, inc)2 (12)
R 5: 12 sc
Sl st.

Tail;
For mouse:
R 1: 4 sc in mc (4)
R 2: inc, 3 sc (5)
R 3-22: 5 sc (20 rows)
Sl st. Fold top of tail flat and 2 sc through both sides across.
F.o.

For cat:
R 1: 4 sc in mc (4)
R 2: (1 sc, inc)2 (6) R 3: (2 sc, inc)2 (8)
R 4: (3 sc, inc)2 (10) R 5-20: 10 sc (16 rows) R 21: (3 sc, dec)2 (8)
R 22: 3 sc, dec, 3 sc (7)
Sl st, fold top of tail flat and 3 sc through both sides across.
F.o.

Body
Make 18 ch.
Make an oval, work on both sides of the chain.
R 1: From the 2nd ch from hook: 16 sc, 3 sc in last st, on the opposite side of the chain: 15 sc, inc (36)
In the next row we will join legs:
R 2: inc, 15 sc, 3 inc, 4 sc together with sc of the 1st leg, 7 sc, 4 sc together with sc of the 2nd leg, 2 inc (42)
R 3: 1 sc, inc, 15 sc, (1 sc, inc)3, 15 sc, (1 sc, inc)2 (48)
For cat: in the next row we will join tail (for mouse: sew tail at R 4 of the body)
R 4: 2 sc, inc, 6 sc, 3 sc together with sc of the tail, 6 sc, (2 sc, inc)3, 15 sc, (2 sc, inc)2 (54)
R 5-9: 54 sc (5 rows)
R 10: 25 sc, dec, 25 sc, dec (52)
R 11: 52 sc
R 12: dec, 24 sc, dec, 24 sc (50)
In the next row we will join arms:
R 13: 29 sc, 3 sc together with sc of the 1st arm, 11 sc, 3 sc together with sc of the 2nd arm, 4 sc (50)
R 14: dec, 23 sc, dec, 23 sc (48)
R 15: 48 sc
R 16: dec, 22 sc, dec, 22 sc (46)
R 17: 46 sc
R 18: 21 sc, dec, 21 sc, dec (44)
R 19: 44 sc
R 20: dec, 20 sc, dec, 20 sc (42)
R 21: 42 sc
R 22: (5 sc, dec)6 (36) R 23: (4 sc, dec)6 (30)
R 24: (3 sc, dec)6 (24) R 25: (2 sc, dec)6 (18)
R 26: (1 sc, dec)6 (12) R 27: (dec)6 (6)
Sl st. F.o.

Insert safety eyes
For mouse: between R 17 and R 18 at the distance of 5-6 st from each other.
For cat: between R 18 and R 19 at the distance of 3 st from each other.

Cheese
R 1: 4 sc in mc (4)
R 2: (inc)4 (8) R 3: (1 sc, inc)4 (12)
R 4: 12 sc
R 5: (2 sc, inc)4 (16) R 6: 16 sc R 7: (3 sc, inc)4 (20)
R 8: 20 sc
Sl st, fold top flat and 10 sc through both sides across.

Circles for cheese (make 3)
With YarnArt Jeans and 2.0 mm crochet hook:
R 1: 6-7 sc in mc

Sausage
Make sl st in the end of the every row and start new row with 1 ch:
R 1: 8 sc in mc (8)
R 2: (inc)8 (16) R 3: (1 sc, inc)8 (24)
R 4: (2 sc, inc)*8 (32)
R 5: 32 sl st
Embroider some stitches with white yarn.