Sec Form 4 Filing - Denbaars Steven @ Palomino Laboratories Inc. - 2025-09-29

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Denbaars Steven 2. Issuer Name and Ticker or Trading Symbol Palomino Laboratories Inc. [ NONE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 313 BRYANT COURT 3. Date of Earliest Transaction (MM/DD/YY) 09/29/2025 (Street) PALO ALTO,, CA94301 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 09/29/2025 J( 1 ) 1,625,000 A 1,750,000 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Warrants $ 1.5 09/29/2025 S( 1 ) 125,000 09/29/2025 ( 1 ) Common Stock 125,000 $ 1.2 125,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Denbaars Steven 313 BRYANT COURT PALO ALTO,, CA94301 X Signatures /s/ Steven Denbaars 10/09/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Per the terms of an Agreement and Plan of Merger, dated September 29, 2025, Palomino Acquisition Co., a subsidiary of Issuer, merged into Rhino Subsidiary Inc. (f/k/a Palomino Laboratories Inc., "Pre-Merger Palomino"). Mr. DenBaars, as a shareholder of Pre-Merger Palomino, received 1,500,000 shares of common stock, par value $0.0001 per share, of Issuer ("Common Stock") in exchange for his Pre-Merger Palomino shares. On September 29, 2025, Issuer closed a private placement offering and, during which, Mr. DenBaars converted his SAFEs into 125,000 Units at a price of $1.20 per Unit. Each Unit consists of one share of the Common Stock and one warrant to purchase one share of Common Stock at an exercise price of $1.50. The warrants expire on the first anniversary of the date the Common Stock is admitted for trading or listed on an Approved Market (as defined in warrant agreement).

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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