Most of the space between your lines comes from the linecaps, I recently asked a similar question at https://topanswers.xyz/tex?q=586
However for your purpose, I think using `\coordinate` might be more appropriate.
@marmot remarked that the connections between your line segments will look better if you draw them in one path instead of splitting them into 6 individual draw commands.
```
\documentclass[tikz,border=0.5cm]{standalone}
\begin{document}
\begin{tikzpicture}[line width=0.3mm]
\coordinate (lt) at (-5,2); % Left top
\coordinate (tm) at (-3,2); % Top-mid
\coordinate (rt) at (-1,1.5); % Right top
\coordinate (rb) at (-1,-1.5); % Right bottom
\coordinate (bm) at (-3,-2); % Bottom-mid
\coordinate (lb) at (-5,-2); % Left bottom
\draw (lt) to[in=160]
(tm) to[bend right]
(rt) to[out=60,in=90,bend left]
(rb) to[bend right]
(bm) to[out=160,bend left]
(lb) to[out=60,in=90,bend left] (lt);
\end{tikzpicture}
\end{document}
```
----
### Rock ducks:
```
\documentclass{standalone}
\usepackage{tikzducks}
\pagecolor{black}
\begin{document}
\begin{tikzpicture}
\duck[mohican=white]
\begin{scope}[scale=0.7,yscale=-1,yshift=-11cm,xshift=-7.3cm]
\fill[blue] (10.6237,8.0262) .. controls (10.6077,8.0254) and (10.5915,8.0316) .. (10.5789,8.0450) .. controls (10.5537,8.0717) and (10.5526,8.1171) .. (10.5765,8.1463) .. controls (10.5766,8.1464) and (10.5766,8.1464) .. (10.5767,8.1465) .. controls (10.5609,8.1506) and (10.5450,8.1548) .. (10.5283,8.1593) .. controls (10.5309,8.1385) and (10.5257,8.1164) .. (10.5120,8.0996) .. controls (10.4881,8.0702) and (10.4484,8.0684) .. (10.4232,8.0950) .. controls (10.3994,8.1204) and (10.3973,8.1621) .. (10.4171,8.1913) .. controls (10.3922,8.1988) and (10.3679,8.2064) .. (10.3428,8.2146) .. controls (10.3480,8.1915) and (10.3432,8.1658) .. (10.3278,8.1469) .. controls (10.3038,8.1177) and (10.2641,8.1156) .. (10.2390,8.1425) .. controls (10.2138,8.1693) and (10.2126,8.2147) .. (10.2365,8.2440) .. controls (10.2381,8.2459) and (10.2400,8.2474) .. (10.2417,8.2491) .. controls (10.2184,8.2578) and (10.1958,8.2668) .. (10.1737,8.2759) .. controls (10.1777,8.2539) and (10.1725,8.2298) .. (10.1578,8.2119) .. controls (10.1341,8.1827) and (10.0943,8.1807) .. (10.0691,8.2076) .. controls (10.0438,8.2344) and (10.0428,8.2798) .. (10.0667,8.3090) .. controls (10.0702,8.3133) and (10.0741,8.3168) .. (10.0782,8.3199) .. controls (10.0616,8.3286) and (10.0460,8.3374) .. (10.0316,8.3463) .. controls (9.8657,8.5358) and (9.2518,9.2376) .. (8.9182,9.5403) .. controls (8.7589,9.6056) and (8.5365,9.7915) .. (8.4256,9.7786) .. controls (8.2723,9.7608) and (7.9603,9.3191) .. (7.8303,9.3921) .. controls (7.7005,9.4652) and (7.9599,9.9365) .. (7.9029,10.0726) .. controls (7.8461,10.2086) and (7.3344,10.3397) .. (7.3723,10.4868) .. controls (7.4099,10.6337) and (7.9369,10.5624) .. (8.0550,10.6642) .. controls (8.1730,10.7661) and (8.1689,11.2888) .. (8.3222,11.3066) .. controls (8.4754,11.3244) and (8.5416,10.8088) .. (8.6714,10.7358) .. controls (8.8014,10.6629) and (9.3103,10.8549) .. (9.3673,10.7188) .. controls (9.4243,10.5828) and (8.9382,10.3356) .. (8.9005,10.1886) .. controls (8.8745,10.0877) and (9.0161,9.8663) .. (9.0697,9.7041) .. controls (9.4245,9.2430) and (10.1121,8.5574) .. (10.1121,8.5574) -- (10.3395,8.5630) -- (10.7962,8.0943) .. controls (10.7962,8.0943) and (10.7497,8.1040) .. (10.6819,8.1201) .. controls (10.6883,8.0963) and (10.6838,8.0692) .. (10.6677,8.0494) .. controls (10.6557,8.0348) and (10.6398,8.0270) .. (10.6237,8.0262) -- cycle;
\end{scope}
\end{tikzpicture}
\begin{tikzpicture}
\duck
\begin{scope}[scale=0.7,yscale=-1,yshift=-9.3cm,xshift=-13cm]
\fill[teal!30!green] (15.8697,6.5711) .. controls (15.8614,6.5720) and (15.8533,6.5758) .. (15.8465,6.5826) .. controls (15.8285,6.6008) and (15.8264,6.6337) .. (15.8421,6.6560) .. controls (15.8421,6.6560) and (15.8421,6.6561) .. (15.8421,6.6561) .. controls (15.8310,6.6584) and (15.8199,6.6607) .. (15.8082,6.6632) .. controls (15.8106,6.6481) and (15.8081,6.6319) .. (15.7991,6.6191) .. controls (15.7834,6.5966) and (15.7561,6.5933) .. (15.7380,6.6115) .. controls (15.7209,6.6287) and (15.7184,6.6587) .. (15.7313,6.6808) .. controls (15.7136,6.6851) and (15.6964,6.6896) .. (15.6787,6.6943) .. controls (15.6830,6.6778) and (15.6811,6.6590) .. (15.6709,6.6444) .. controls (15.6553,6.6220) and (15.6279,6.6187) .. (15.6099,6.6369) .. controls (15.5918,6.6551) and (15.5898,6.6880) .. (15.6055,6.7102) .. controls (15.6065,6.7117) and (15.6077,6.7129) .. (15.6089,6.7143) .. controls (15.5923,6.7195) and (15.5763,6.7250) .. (15.5606,6.7307) .. controls (15.5641,6.7148) and (15.5620,6.6972) .. (15.5524,6.6834) .. controls (15.5367,6.6609) and (15.5093,6.6576) .. (15.4913,6.6759) .. controls (15.4731,6.6940) and (15.4710,6.7269) .. (15.4867,6.7492) .. controls (15.4889,6.7524) and (15.4916,6.7552) .. (15.4943,6.7576) .. controls (15.4827,6.7631) and (15.4717,6.7687) .. (15.4615,6.7745) .. controls (15.3017,6.9479) and (14.5020,7.7551) .. (14.5020,7.7551) .. controls (14.4423,7.5545) and (12.3590,8.5157) .. (12.8559,8.5074) .. controls (13.8089,8.4789) and (13.9451,8.6232) .. (13.9118,9.5234) .. controls (13.8887,10.0435) and (14.7855,8.0257) .. (14.6317,7.8966) .. controls (14.6317,7.8966) and (15.1732,7.3377) .. (15.5113,6.9316) -- (15.6676,6.9467) -- (15.9946,6.6290) .. controls (15.9946,6.6290) and (15.9622,6.6338) .. (15.9149,6.6422) .. controls (15.9201,6.6252) and (15.9181,6.6054) .. (15.9075,6.5902) .. controls (15.8977,6.5762) and (15.8834,6.5696) .. (15.8697,6.5711) -- cycle;
\end{scope}
\end{tikzpicture}
\begin{tikzpicture}
\duck[mullet=magenta,xscale=-1]
\begin{scope}[scale=0.7,yscale=-1,yshift=-9.3cm,xshift=-4.5cm]
\fill[red] (1.3888,6.4104) .. controls (1.3750,6.4104) and (1.3614,6.4166) .. (1.3512,6.4290) .. controls (1.3375,6.4458) and (1.3339,6.4693) .. (1.3395,6.4905) .. controls (1.2813,6.4736) and (1.2415,6.4631) .. (1.2415,6.4631) -- (1.6347,6.8935) -- (1.8294,6.8979) .. controls (1.8294,6.8979) and (3.0750,8.2239) .. (2.8868,8.3094) .. controls (2.8596,8.4480) and (2.5629,8.3565) .. (2.5573,8.4975) .. controls (2.5491,8.7012) and (2.8901,8.6298) .. (3.0122,8.7673) .. controls (3.1572,8.9310) and (3.1168,9.3064) .. (3.3071,9.3884) .. controls (3.8903,8.9113) and (4.0978,9.0483) .. (4.3801,8.9771) .. controls (4.9068,8.8440) and (3.8263,8.2951) .. (3.4358,8.0672) .. controls (3.2843,7.8952) and (3.2828,7.3805) .. (3.0738,7.4569) .. controls (2.9420,7.5048) and (3.1683,7.8731) .. (3.0409,7.9371) .. controls (2.9739,8.0213) and (2.0889,6.9480) .. (1.8973,6.7159) .. controls (1.8849,6.7075) and (1.8716,6.6991) .. (1.8573,6.6908) .. controls (1.8608,6.6883) and (1.8642,6.6853) .. (1.8671,6.6817) .. controls (1.8874,6.6569) and (1.8863,6.6170) .. (1.8646,6.5925) .. controls (1.8429,6.5679) and (1.8089,6.5681) .. (1.7885,6.5927) .. controls (1.7761,6.6078) and (1.7718,6.6287) .. (1.7752,6.6483) .. controls (1.7563,6.6393) and (1.7369,6.6305) .. (1.7169,6.6219) .. controls (1.7184,6.6204) and (1.7199,6.6192) .. (1.7213,6.6175) .. controls (1.7417,6.5929) and (1.7406,6.5528) .. (1.7189,6.5284) .. controls (1.6971,6.5038) and (1.6631,6.5039) .. (1.6429,6.5286) .. controls (1.6297,6.5447) and (1.6257,6.5670) .. (1.6303,6.5874) .. controls (1.6087,6.5792) and (1.5878,6.5715) .. (1.5664,6.5638) .. controls (1.5833,6.5390) and (1.5815,6.5024) .. (1.5608,6.4791) .. controls (1.5391,6.4547) and (1.5051,6.4547) .. (1.4849,6.4795) .. controls (1.4732,6.4937) and (1.4688,6.5128) .. (1.4712,6.5313) .. controls (1.4569,6.5266) and (1.4433,6.5223) .. (1.4298,6.5180) .. controls (1.4299,6.5180) and (1.4299,6.5180) .. (1.4300,6.5179) .. controls (1.4501,6.4933) and (1.4490,6.4534) .. (1.4273,6.4288) .. controls (1.4165,6.4164) and (1.4026,6.4103) .. (1.3888,6.4104) -- cycle;
\end{scope}
\end{tikzpicture}
\end{document}
```
