The Dink Network

Just make his legs move slower? That's easy! If you actually wanted to make Dink walk slower or faster, it would be a little bit more complicated; unlike other sprites, sp_speed doesn't work on him (nor sp_frame_delay, if memory serves), so you instead have to use the specific set_dink_speed command, which only works with numbers from 4 to 1, with 4 being the slowest and 1 the fastest.

Anyway,

load_sequence_now graphics\dink\walk\ds-w1- 71 100 38 72 -14 -9 14 9
load_sequence_now graphics\dink\walk\ds-w2- 72 100 37 69 -13 -9 13 9
load_sequence_now graphics\dink\walk\ds-w3- 73 100 38 72 -14 -9 14 9
load_sequence_now graphics\dink\walk\ds-w4- 74 100 38 72 -12 -9 12 9
load_sequence graphics\bonuses\bottles\botl-b 75 75 13 43 -12 -9 9 7

the part in bold is the line that determines how fast each frame of the animation plays. You can also change the speed for only a few frames in a sequence, like in Dink's punch animation:

set_frame_delay 102 2 100
set_frame_delay 104 2 100
set_frame_delay 106 2 100
set_frame_delay 108 2 100

EDIT: I see you already did that! I should try that reading posts thing sometime. It's a script problem with Dink, since some scripts overwrite the default delay in his walk sequence. See item-fst.c, for example:

init("load_sequence_now graphics\dink\walk\ds-w1- 71 43 38 72 -14 -9 14 9");
init("load_sequence_now graphics\dink\walk\ds-w2- 72 43 37 69 -13 -9 13 9");
init("load_sequence_now graphics\dink\walk\ds-w3- 73 43 38 72 -14 -9 14 9");
init("load_sequence_now graphics\dink\walk\ds-w4- 74 43 38 72 -12 -9 12 9");

init("load_sequence_now graphics\dink\walk\ds-w6- 76 43 38 72 -13 -9 13 9");
init("load_sequence_now graphics\dink\walk\ds-w7- 77 43 38 72 -12 -10 12 10");
init("load_sequence_now graphics\dink\walk\ds-w8- 78 43 37 69 -13 -9 13 9");
init("load_sequence_now graphics\dink\walk\ds-w9- 79 43 38 72 -14 -9 14 9");

init("load_sequence_now graphics\dink\idle\ds-i2- 12 250 33 70 -12 -9 12 9");
init("load_sequence_now graphics\dink\idle\ds-i4- 14 250 30 71 -11 -9 11 9");
init("load_sequence_now graphics\dink\idle\ds-i6- 16 250 36 70 -11 -9 11 9");
init("load_sequence_now graphics\dink\idle\ds-i8- 18 250 32 68 -12 -9 12 9");

init("load_sequence_now graphics\dink\hit\normal\ds-h2- 102 75 60 72 -19 -9 19 9");
init("load_sequence_now graphics\dink\hit\normal\ds-h4- 104 75 61 73 -19 -10 19 10");
init("load_sequence_now graphics\dink\hit\normal\ds-h6- 106 75 58 71 -18 -10 18 10");
init("load_sequence_now graphics\dink\hit\normal\ds-h8- 108 75 61 71 -19 -10 19 10");

There are also a few others, mostly load game related scripts. start-2.c and escape.c, at least.